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http://www.archive.org/details/practicalalloyinOObuch 



PRACTICAL 
ALLOYING 



A Compendium of alloys and 
processes for brass founders, 
metal workers and engineers. 

By John F/Buchanan 

Author of 

Brass Founders' Alloys 

and 

Foundry Nomenclature 



SECOND EDITION 



Published by 

The Penton Publishing Co. 

Cleveland, Ohio 



TShSo 



Copyright in the United States 

and 

Entered at Stationers' Hall, London, 

1920 

■ The Penton Publishing Co. 

Cleveland, Ohio 



FEB 2! 1921 
§)CU608434 



THE PENTON PRESS. CLEVELAND 



i 

CONTENTS 

CHAPTER I 
Metal Refining — Ancient and Modern 1 

CHAPTER II 
History and Peculiarities of Alloys 14 

CHAPTER III 
The Properties of Alloys 25 

CHAPTER IV 
Some Difficulties of Alloying 41 

CHAPTER V 
Methods of Making Alloys 52 

CHAPTER VI 
Color of Alloys 65 

CHAPTER VII 
The Notation of Alloys 73 

CHAPTER VIII 
Standard Alloys 80 

CHAPTER IX 
Foundry Mixtures 118 

CHAPTER X 
White Metals 133 

CHAPTER XI 
Solders, Novelty Metals, etc 138 

CHAPTER XII 
Fluxes for Alloys 150 

CHAPTER XIII 
Gates and Risers for Alloys 163 

CHAPTER XIV 
Ab'out Crucibles 174 

CHAPTER XV 

Testing Alloys 181 

Tables, etc 184 

Index 192 



PREFACE 

THE progress made in the production of alloys within the 
last two decades has been phenomenal. There is no end 
to the invention of new alloys, and the number of varia- 
tions in the composition of alloys that have long ago 
passed the experimental stages, is simply overwhelming. Out 
of the multitudinous mixtures advocated and employed in the 
practical and constructive arts, it is no easy matter to select, 
or even to classify the metals of importance. 

The "battle of the bronzes" has been going on for at least 
thirty years, and the honors have fallen to phosphor bronze, 
aluminum bronze and manganese bronze at different periods. 
In other branches of the metal industry similar progress is 
being recorded. New alloys are being introduced or new addi- 
tions are being made to old alloys, and new records are being 
made in alloy practice. It is needless to add that new difficul- 
ties are also presenting themselves, and these are the things that 
make effort worth while. 

This book professes to be no more than a handy guide to 
the practical alloys and processes. The bulk of the matter 
originally appeared in "The Foundry" and other trade maga- 
zines, and judging by the number of inquiries addressed to me 
on many of the subjects treated, the reappearance of the 
articles in book form should be hailed with interest. 

J. F. Buchanan. 



PRACTICAL ALLOYING 



METAL REFINING— ANCIENT AND MODERN 

TO the average individual, the universe is a mass of organic 
and inorganic substances regulated 'by the inscrutable 
laws of an all-wise Providence; to the philosopher, it is 
simply ''harmonious matter;" but to the student of ap- 
plied sciences it presents an inexhaustible array of forces and 
elements, which lend themselves to analytic and synthetic observa- 
tion. Thus, in the view of the scientist, the spectroscope and 
the balance may be said to prove all things, while the blowpipe 
and the melting pot enable him to hold fast that which is good. 
It is the province of science to investigate. The chemist and the 
physicist have to determine the nature and limits of all the ma- 
terial things in their ultimate relations. We may take pride, 
therefore, in the long and ever-increasing list of elementary sub- 
stances compiled by the noble army of workers who have en- 
deavored to unravel for us the mysteries of earth and space. The 
ancients supposed fire, air, earth and water to be the fundamental 
constituents of the universe, and these compounds are still known 
in literature as "the elements." Modern science, however, de- 
fines the simple or elementary bodies as "those substances which 
do not admit of analysis." Up to the present time over seventy 
such substances have been isolated. They are recognized as 
metallic and non-metallic bodies, but the metals are an over- 
whelming majority. Midway between the metals and non- 
metals four elements — sulphur, phosphorus, arsenic and silicon — 
designated metalloids, occur. The distinction between a metal 
and a metalloid is a purely artificial one, based on physical rather 
than chemical standards. The metals are characterized by the 



Practical Alloying 



possession, in varying degrees, of a wide range of properties, as 
ductility, malleability, fusibility, metallic lustre, sonorousness and 
thermal and electrical conductivities. The useful metals are elec- 
tro-positive, and with few exceptions, they readily combine with 
electro-negative bodies, such as oxygen, sulphur, chlorine, etc. 
Consequently, the largest bulk of the metals in the earth exist in 
the mineral state, as ores, requiring a separation of the compon- 
ents^ before they can be put to any practical use. It is with 
metals as with everything else in nature — the useful members 
exist in greater abundance than do those of more superficial 
qualities. 

Antiquity of the softer metals. — Copper, lead, tin, iron, gold, 
silver and mercury appear to have been known from a remote 
antiquity. They are mentioned in Holy Writ and there is every 
reason to believe that they were applied in many ways by the 
Egyptians, Persians, Hindoos and Chinese, in the earlier epochs 
of human history. Obviously, the crude methods employed by 
the ancients for the reduction of the metals greatly restricted 
their application. Their rude furnaces would reduce only the 
richest ores in small quantities and very imperfectly. The early 
history of metallurgy is somewhat obscure. Egypt — the birth- 
place of astrology, alchemy and the liberal arts, and the first of 
old world empires — is known historically and by exploration, as 
the home of many manufacturing processes, indicating a compre- 
hensive knowledge of refractory materials, especially earths and 
metals. The Egyptian potters and refiners have been the models 
for artists, in form and color, down the generations. Prehistoric 
metal workers were undoubtedly engaged in fashioning such 
metals as are known to exist in the free or native condition. The 
seven elements already mentioned, with possibly a copper cala- 
mine compound, sometimes called golden-copper or native brass, 
comprised the stock-in-trade of the metal workers up to the be- 
ginning of the Christian era. Sacred and profane histories and 
the ancient mythologies contain many references to the metals 
and metal workers of that early period, so that Tubal Cain, Vul- 
can and the Cyclops, are names typical of metal workers unto this 
day. Exactly how much knowledge of metallurgic processes the 
early artificers possessed it would be difficult to surmise ; but their 



Metal Refining — Ancient and Modem 



skill in handicrafting metals for architectural and decorative pur- 
poses is beyond dispute. The Bible has made us familiar with 
some of the early metal refining processes, products and appli- 
ances, and it is there we trace the Genesis of metallurgy. 

The fire, the pure metal, and the dross are always related as 
cause and effect. Gold is mentioned as being refined with silver, 
which sounds like the first alloy on record, and Job says : "Surely 
there is a place for gold where they fine it;" and again, "Iron is 
taken out of the earth and brass is molten out of the stone." 
Here let me explain that the word "refining" is applied, in tech- 
nical circles, only to the later stages of the metal extraction 
processes, indicating the separation of impurities from metallic 
compounds ; but it has an older and more comprehensive signifi- 
cance, making it embrace all the operations of reducing as well 
as purifying and alloying metals; and in order to avoid tedious 
distinctions, I take the liberty of using the term in its widest 
application. 

Metal refining and alloying an ancient art. — Practical alloy- 
ing, or the art of refining metals and alloys of metals, is an 
ancient pursuit which has led to many important discoveries; it 
has also been greatly instrumental in furthering the progress of 
mechanical science. It is always interesting and instructive to 
trace the arts and inventions to their origins. A new idea may 
cause a sectional uneasiness, but an old one never loses its power 
to guide and uplift the activities of the race. When the world 
was young and the children of men had leisure to dream, the 
interpreter of visions was a power in the land; magic became a 
fine art and astrology the first science — music and hieroglyphics 
following in natural sequence. Husbandry was the essential oc- 
cupation of mankind until he learned that he could not live by 
bread alone. Worship made calls on his better nature, and these 
were answered, mistakenly, but sincerely, in the graven images 
of the semi-barbarous peoples. Even Israel, the chosen race, 
lapsed into idolatry. Thus, Aaron's golden calf became the 
forerunner of frequent failures as well as the first recorded work 
in metal founding. Such a beginning was befitting this industry, 
for there are many misguided workers engaged in founding met- 
als, even now. Did not Jeremiah establish his reputation as a 



Practical Alloying 



prophet when he said : "Every founder is confounded 'by the 
graven image."* Incidentally, the destruction of this golden calf 
sheds some light on the matter of reducing metals in those early 
days. Moses "took the calf and burnt it in the fire, and ground 
it to powder, and strewed it upon the water." These processes 
are characteristic of some ancient methods of gold refining, and 
the granulation of metals by strewing them upon water is still 
practiced in the manufacture of hard solders and shot metal, as 
well as in some of the modern methods of extracting metals from 
the earthly matter with which they are generally associated. 

In all ages, it has been the aim of the metal refiner to bring 
out and enlarge the useful qualities of the metals, and the prog- 
ress of metallurgic processes in recent times demonstrates the 
desirability of having the practical arts based upon scientific 
principles. We have learned that the chemical properties of 
most metals are such that only their salts are found in nature; 
but the ancient refiner, with his four "elements" and many empir- 
ical laws, made slow advances and few discoveries in the working 
of metals. Up to the time of Pliny, or the beginning of the Chris- 
tian era, the metals were reduced, smelted and mixed with 
scarcely any definite application of chemical knowledge and with 
little or no effort to get rid of impurities, excepting, perhaps, in 
the case of the precious metals — gold and silver. Casting oper- 
ations were necessarily restricted. Alloys other than the natural 
product of the ordinary smelting operations were practically un- 
known. A few mechanical processes, as the calcination and 
cupellation of metals, served for the separation of the noble and 
ignoble elements ; and the proper use of fluxes had not yet been 
discovered. In the middle ages, the alchemists were fired with 
the hallucination of making gold. They formed into leagues ; 
worked in secret upon some mystical formula ; adopted signs, 
zodiacal and religious ; and aimed, at different periods, to dis- 
cover, first, an alkahest, or universal solvent ; second, the phil- 
osopher's stone — a substance for transmuting base metals into 
gold ; and third, the elixir of life — a liquor supposed to have the 
power of prolonging man's existence. 



*Jeremiah 10:14. 



Metal Refining — Ancient and Modem 



Work of the alchemists. — These dreams of the alchemists — 
like the dream of perpetual motion — are still unfulfilled, but 
Utopia is always in the future, and every new discovery seems to 
stir up hope in the prophetic truth of human imaginings. Scien- 
tific, like other history, repeats itself. Men pursue old fancies 
and discover new forces by the way. Recent researches seem 
to be overturning laws which scientists of former periods were 
at great pains to determine. Thus, with the advent of radium, 
Dalton's atomic theory is said to be in danger, the law of the 
permanence of matter is in a precarious position, and if it be true, 
that uranium and other metals develop radio-activity, the greatest 
dream of the alchemists — the transmutation of metals is likely 
to materialize. 

The desire for gold is much older than King Midas. The 
mystics and magicians of the early Egyptian and Persian civil- 
izations indulged in transmutation theories. It took centuries of 
alchemical research to undeceive the later schools about the gold- 
in-everything craze. The disappearance of the Magi and the 
fall of the Roman Empire opened up the way for the development 
of systematic chemistry and the introduction of the new indus- 
trialism. Our increased knowledge of the cosmos has been of 
infinitely greater value than the mere discovery of an alkahest; 
nevertheless, we are indebted to the alchemists, and to the minute- 
ness of their searchings for the philosopher's stone, for the dis- 
covery of many invaluable processes and startling phenomena in 
the realms of chemistry and physics, and also for introducing to 
us that group of interesting bodies, termed the metallic alloys. 

Chemistry and metallurgy are so intimately related that they 
require collateral study; they are allied as theory and practice in 
metal refining processes. Chemical science may be said to lay 
down the law, and be the theoretical basis of metallurgie oper- 
ations, while metallurgy, viewed as a manufacturing art, and by 
right of its historical precedence, may be considered as the prac- 
tical foundation of chemistry. Art and empiricism have always 
preceded science and dogma. Astrology preceded astronomy. 
Alchemy preceded chemistry, and the ancient metal refining proc- 
esses paved the way for the more complete metallurgy of today. 

Chemistry and metallurgy. — Passing from the ancient to the 



Practical Alloying 



modern aspects of metal refining, we are confronted with the 
immensity of the subject. A brief summary of the processes 
involved in the reduction and refining of one of the metals would 
require a book — and a more gifted writer. Having regard, then, 
to the scope of this work, we must be content with a general 
survey of the vast field, focusing the simple principles and the 
more important methods of smelting and alloying metals, down 
to our own times. 

Ores may be described as chemical compounds of metallic 
and non-metallic elements, from which the metals are generally 
obtained "by promoting a change in the chemical equilibrium." 
The nature of the operations by which metals are extracted from 
their ores depends on the chemical affinities of the metals to be 
extracted. 

Nature works by a system of laws and affinities ; and, in 
treating metals, the best results have been obtained by imitating 
the processes by which metallic compounds are built up or dis- 
sociated in nature. Of necessity, the metallurgist is forced to 
observe the chemical reactions following upon the elaborate proc- 
esses involved in the separation of gangue or earthy matter from 
the purely metallic constituents of an ore. The ores from which 
most of the metals are obtained, occur in such great variety of 
combination and in such diverse conditions, that no general sys- 
tem of treatment could be devised for the reduction of any one 
class. Metallic oxides, sulphides, carbonates and silicates con- 
stitute the majority of the minerals yielding the useful metals. 

The value of an ore depends upon the metals it contains and 
upon its susceptibility to metallurgic treatment. Very often the 
presence of the precious metals influences the choice of a refining 
process and necessitates more careful handling and more ex- 
haustive treatment of the ores. But the metallic content is not 
always the most important consideration in the treatment of an 
ore. Some ores contain sufficient suitable fluxing material to 
reduce the metallic contents in the form of coarse metal ; others 
lack this excellent property and have to be fed with artificial 
fluxes. In recent years, many low grade ores, which could not 
be economically reduced in former times, have, owing to the more 
exhaustive and economical reactions of modern metallurgy, and 



Metal Refining — Ancient and Modern 



the manufacture of practical by-products from the materials of 
reduction, been increased in value beyond their intrinsic worth. 

Metallic combinations. — Metals may exist in any of the three 
states of matter, solid, liquid or gaseous, the condition varying 
with and being nearly always determined by the temperature. 
The possibilities in the way of metallic combinations are infinite. 
Metals combine with each other and with other elements in 
nature, producing compounds the decomposition of which de- 
mands a close observance of chemical and physical laws, as well 
as an intimate acquaintance with the mechanical processes of 
refining. The association of different elements and the chemical 
conditions binding them together can only be broken up by the 
application of suitable chemical reagents. Heat is the principal 
agency by which the cohesive force of materials is diminished, 
and it is because the application of heat promotes the operation 
of the laws of chemical energy that the metallurgist is so strongly 
addicted to the agency of fire. 

Treatment of ores. — The treatment of the ores for obtaining 
the metals is mechanical and chemical. The mechanical treat- 
ment is preliminary to the roasting and reduction processes and 
consists in crushing, washing and classifying the ores accord- 
ing to their richness and the nature of the gangue. The proc- 
ess is known as concentration and its action is based upon the 
different specific gravities of the substances which are associated 
in the ore, advantage being taken of the different speeds at which 
their particles will subside in a column of water. Ores which 
are mineralized in large masses, or crystals, are adapted for 
coarse concentration ; on the contrary, ores which contain the 
valuable mineral in a finely divided state must be crushed finer in 
order to liberate the finer particles. 

The degree of fineness to which an ore should be crushed 
depends on the nature of the mineralized ingredients. The solvent 
action of water eliminates worthless substances, diminishes the 
labor of dressing and leaves the metalliferous contents in a con- 
centrated form. Many ores of lead, zinc, copper and iron are 
prepared for heat treatment, or chemical processes, by the coarse 
method of concentration, but the ores of silver, gold and tin 
usually require more careful dressing and fine concentration. 



Practical Alloying 



When the chemical nature of the ore is known, it is generally 
easy to arrange conditions which will assist in the reduction of 
the metal. It is thus the concentrates obtained from the mills 
are prepared for the further processes of roasting and smelting, 
or, if the precious metals are involved, chlorination, cyanidation 
and amalgamation. 

The local facilities and the chemical susceptibilities of the 
concentrates, determine the smelting process most likely to be 
successful. In most smelting operations, the reduction is effected 
by the abstraction of oxygen from some oxidized compound of a 
metal, or, as it is technically termed, deoxidation. On the other 
hand, oxidation is frequently important in metallurgical proc- 
esses, as it is a means by which substances that are readily oxi- 
dized may be separated from others which are less readily 
oxidized. 

Many ores contain substances which generate volatile com- 
binations under the influence of heat and air. This process is 
technically known as roasting; it removes volatile impurities and 
is generally preliminary to the fusion or smelting operations by 
which the reduction of the metals contained in the ores is accom- 
plished. 

Some ores and alloys are separated by the process of liqua- 
tion, i. e., by taking advantage of the difference in fusibility of 
the components. For example, when an ore is exposed to a 
gentle heat sufficient only to melt the most fusible constituent of 
the mass, it is separated from the unmelted residue, or in the 
case of alloys, if the elements do not enter into chemical union, 
there is always a tendency for them to separate out according to 
their densities and in relation to their fusible properties. 

The solvent action of certain liquids frequently affords a 
convenient means of separating metals from the earthy matter 
enveloping them, consequently many of the ores are treated with 
acid or other liquids previous to the precipitation and reduction 
of the metals contained therein. 

It would be difficult to go into the details of metal manu- 
facture since the operations vary with the nature of ths ores and 



Metal Refining — Ancient and Modern 



the value of the metals which they contain. Prof. Roberts- 
Austen, in his "Introduction to Metallurgy," has given a general 
summary of the methods of extracting and reducing metals from 
the ores, under the following heads : 

1. — Liquation. 

2. — Distillation and sublimation. 

3. — By the reduction of metallic oxides at high temperatures 
as (2PbO + C = 2Pb + C0 2 ). 

4. — By the decomposition of metallic sulphides by means of 
iron at a high temperature, as seen in the equation, (Pb S + Fe 
= Pb + Fe S). 

5. — By cupellation, which is probably the oldest method of 
extracting metals from their ores. When lead is molten it 
oxidizes rapidly, forming litharge, which has the property of 
dissolving other metallic oxides and combining with them into 
a slag. 

6. — By amalgamation, i. e., by taking advantage of the 
powerful solvent properties of mercury. 

7. — By electrolysis. 

8. — By crystallization, as in Pattison's method of extracting 
silver. 

9. — By the wet process — dissolving in acids and precipitat- 
ing; or forming compounds which can be acted upon by suitable 
reagents. 

This by no means exhausts the list of methods by which 
metals may be extracted ; there are many auxiliary processes and 
combination methods which could only be dealt with by describing 
the complete metallurgy of the metals. 

This is especially true as regards the recovery of the "noble" 
metals. Metal refiners have such a wide range of methods to 
select from that it is sometimes a hard matter to decide which is 
the best treatment for a particular ore. The fact is, many good 
mines have failed to pay dividends because the economies of the 
extraction processes did not receive proper attention. 

Whatever method of decomposing the mineral may be 
adopted, wet or dry, all the labors of metallurgical processes are 
directed to the same end, to reduce the substance to the metallic 
condition and to separate impurities from the metals recovered. 



10 Practical Alloying 



Every new reaction or change of the chemical relations of the 
material, contributing to its decomposition, may be turned to ac- 
count for the recovery of the metal, or for the manufacture of 
some commercial product. Hence the increase in the number of 
metallurgic processes, and the adoption of combination methods 
giving better control of the commercial values. 

Treatment of complex ores. — Perhaps the most prominent 
feature of modern metallurgy is the thoroughness with which 
the various elements contained in the ores, or in the resulting 
metals, are marshalled and utilized. In these days, the methods 
of isolating and purifying the metals are better understood, the 
complex ores can be more fully treated, and the results regulated 
with more precision than ever before. There are few negligible 
quantities contained in the ores nowadays. The metallurgic 
methods are so comprehensive, and the chemical reactions so well 
controlled, that the real value of the various ores is not to be 
gaged by the proportions of the metals they contain. There is 
no doubt that the metal refining industry, or, to be precise, applied 
metallurgy, is undergoing a revolution. More is being taken 
out of the ores "now than was possible a few years back ; the 
quality of the metals produced is superior, the grades are more 
uniform, and the cost of production is being steadily reduced. 

To illustrate this point I quote this paragraph from a current 
newspaper: ''Broken Hill ores, which hitherto have only been 
treated for the silver and lead content, are now to be worked for 
zinc and sulphur also." Thus, from the residue of an older 
metallurgical process, a new industry is to be created ; and by the 
additional profit from zinc (16 per cent), which was formerly 
ignored, and the manufacture of sulphuric acid, increased pros- 
perity, in this instance, is assured. 

Yet another example of remarkable development made in 
recent years is the smelting of concentrator slimes, which were 
practically refuse. By a simple process of sintering, or kiln 
roasting, and then smelting, thousands of tons are being con- 
verted into marketable metals — and profit! 

As illustrating a modern process designed to economize the 
products of ores containing precious metals combined with vola- 
tile metals and elements, take Dr. Hoepfuerer's method of recov- 



Metal Refining — Ancient and Modern 11 

ering zinc from argentiferous blends in which the percentage of 
iron is too large to permit the ordinary distillation method being 
used. "The ores are at first roasted with common salt, resulting 
in the production of zinc chloride and sodium sulphate. These 
two soluble salts are then leached out, and the latter separated 
from the former by crystallization in the cold. The zinc chloride 
is then treated electrolytically, using carbon anodes, and for 
cathodes, a revolving plate of zinc. The chlorine as it escapes 
is absorbed by lime, making it a marketable product. The 
precious metals remain in the leached residues in the tanks." 
If rich enough, these may be sent direct to the smelter; if not, 
they would require concentration. 

This example is typical of the modern improvements and 
economies effected by studying the properties and capabilities of 
the associated minerals, ores, fluxes and fuels, and the obvious 
advantage of employing electricity for the reduction and separa- 
tion of the metals. 

Electrical reduction of ores. — The selling price of a metal 
depends largely upon the readiness with which it is reduced from 
its ores. Only a few metals are reduced to the metallic state 
from their compounds by heat alone. Assistance has to be 
rendered by reducing agents. In modern metallurgy, the electric 
current promises to become one of the most important of such 
agents, as its action is direct and readily applied. The problem 
is to separate the metal from the non-metal with which it is in 
combination. The current does this with no intermediate steps. 
Thus, common salt fuses at a red heat, and if a current is passed 
through the molten mass between carbon electrodes, the metal 
sodium is liberated at one end and the gas chlorine at the other. 
Great technical difficulties have been met in the application of this 
simple method, but they have now, to a large extent, been over- 
come. An older plan is to heat the ore with carbon, which, for 
example, takes away the oxygen of a metallic oxide to form the 
gaseous carbon dioxide, which escapes. Hydrogen reduces oxides 
in a similar way, water being formed. Another plan of reduc- 
tion is to use another metal, particularly aluminum, which is able 
to replace it in the compound, and so set it free. With aluminum, 
great evolution of heat takes place, sufficient to melt the reduced 



12 Practical Alloying 



metal. This is the basis of a well-known process for hard solder- 
ing steel rails, and so forth. In a like way, sodium was formerly 
largely used in the reduction of the rarer metals, which greatly 
increased their cost ; but now electric practice is replacing it. A 
very important case of reduction is that by potassium cyanide, 
which takes the oxygen of an oxide to form a cyanate. More 
and more, however, the current is coming into play. Thus, 
formerly, the production of phosphorus implied the treatment of 
bone-ash, or natural phosphates, with sulphuric acid, but recent 
improvements in the electric furnace have made it possible to 
smelt either, mixed with charcoal, for the direct production of 
the element. The advantage here lies in the enormously high 
temperature of the electric furnace. To sum up, the modern 
methods of producing metals for the market are characterized by : 

First, the systematic observance of chemical principles. 

Second, the adoption on a large scale of laboratory methods. 

Third, economy of power and material. 

Fourth, the introduction of electricity as a means of decom- 
posing metallic compounds. 

Electro-technology has made enormous strides in the last 
decade. Electrolysis and the electric furnace have added many 
interesting products to the metal worker's storehouse. The 
former has solved the problem of producing pure metals on a 
commercial basis, while the latter has rendered possible the 
reduction and union of many refractory metals which formerly 
were not feasible. The progress made in the manufacture of 
self-hardening steels since the adoption of the electric furnace 
for the commercial reduction of chromium, tungsten and other 
hardly fusible metals, affords a striking proof of the improve- 
ments effected. 

But besides furnishing power for the engineer, heat for the 
metallurgist, attraction for the chemist, light for the world and 
"vitality for weak men" as the electropathist puts it — electricity 
has many other uses awaiting development. Dr. Borchers says 
"there is no metal incapable of being reduced by electrically 
heated carbon," i. e., the electric arc. Electricity has long been 
known to be a potent factor in the decomposition of metallic 
substances, but metallurgists are only beginning to take advantage 



Metal Refining — Ajicient and Modern 13 

of the fact. Electro-conductivity has been proposed as a means 
of testing the purity of the metals ; indeed, this has already been 
accomplished with copper and aluminum. So it is only a matter 
of time till a standard of conductivity is tabulated for all the 
metals in a state of purity. We shall then have established a 
cheap test of the purity of metals. 

Other proposals connected with the electrolysis of dissolved 
or fused metals, or metallic compounds, are also meeting with 
practical application, but this is hardly the place for a statement 
of electro-chemical theories. Certain it is that electricity has 
proved an economical power in metallurgy. It can be made to 
subdue the elements to the last atom. It may be said to fulfill 
the functions of the elixir of life and the philosopher's stone in 
one act, and now that modern scientists have wedded this spark- 
ing Vesta to the strenuous Vulcan, we may expect a numerous 
and gifted offspring. A well-known London humorist deplores 
the abolition of London fog by means of electricity ! He says : 
"Electricians must learn sooner or later that not everything 
which can be done by electricity ought to be done." Metallurg- 
ists must learn this, too, and no doubt many of the old-fashioned 
metal refiners, who have not yet acquired the electric habit, will 
agree with the sentiment even if they fail to recognize the 
humor. The changes :which have taken place in the general 
treatment of ores, even in the preliminary dressing and mechan- 
ical processes, would astonish the most informed refiner of a 
previous generation, for just as the introduction of the hot blast 
in the early days of iron and steel development created new con- 
ditions of working iron ores, so the later improvements in 
mechanical appliances and the newer applications of chemical and 
electrical principles have advanced and extended the operations 
and productions along the whole range of the metals. 



II 

HISTORY AND PECULIARITIES OF ALLOYS 



THE story of the alloys forms an important chapter in the 
history of our planet. They are closely identified with the 
struggles of mankind to gain the mastery in empire, and 
in the arts and industries. It is worthy of note, that the 
supremacy of the nations, in successive epochs, has depended as 
much upon engineering, or the skill of the metal workers, as upon 
what is called the "force of arms." Even in our own times, the 
superior mechanism of a modern rifle has altered the political 
arrangement of the map ; and in times of peace the most favored 
nation has generally been the most up-to-date, industrially. The 
ascendant nations have ever been in the van of scientific enlight- 
enment and achievement. Warfare, which was once a matter of 
big battalions, is now a question of mobility and big batteries. 
Engines of war have always had some influence in adjusting the 
positions of the powers, and in many of the revolutionary periods 
armaments have been accounted more than troops. All of which 
shows that a knowledge of mechanics and the control of metals 
are of some importance in deciding the destinies of the nations. 
Alloys have undoubtedly played a prominent part in the advance- 
ment of civilization. Historically, they are co-eval with the 
creation — the mention of brass in Genesis leads to this inference. 
If we are to credit the early records, brass was first made in the 
bowels of the earth. It was a prehistoric discovery of nature. 
That brass was known to the ancients is beyond dispute. Mines 
containing ores from which this yelllow metal was produced, were 
held in high esteem, but it is doubtful if the early metal workers 
had any definite knowledge enabling them to control the product. 



History and Peculiarities of Alloys 15 

It is no uncommon thing for the natural excellencies of a mine, 
or its ores, to create a world-wide reputation for the metals they 
yield. "Veille Montagne" zinc, "Lowmoor" iron, "Banca" tin 
and "Lake" copper are modern examples of such fame. But not 
to lose sight of the historical view of our alloys, we must stretch 
back to mark the transition from the neolithic or new Stone Age, 
to the Bronze Age. What we term the Bronze Age, started early 
and continued late in the world's history, and even unto this day 
bronze shares the honors with steel and iron in constructive and 
ornamental metal work. Brass and bronze are often confounded 
by people who ought to know better. They are two distinct alloys 
— the former being composed of copper and zinc, and the latter 
being a mixture of copper and tin — and there are decided con- 
trasts in their characteristic properties. 

Bronze in the world's history. — The world's history might 
easily be written in chapters on bronze, the opening numbers of 
which may be roughly summarized thus : 

Chapter I. — Palaeolithic man, worn with the worries of the 
Stone Age and grumbling at the necessity for renewing the cut- 
ting edge of his uncouth implements, expressed in the hearing 
of his grandson a longing for more enduring tools. The boy, 
eager to acquit himself, after long and adventurous search, 
brought forth, triumphant, from a fissure in the Great Rock, a 
nugget, which, for want of a better name, was afterwards callecl 
Aurichalcum, i. e., golden copper. And thus originated the first 
artificer in metals ! 

Chapter II. — The artificers grew and multiplied, and the 
harvests being sooner garnered with the improved appliances, 
they waxed thoughtful, but no less industrious. Bending their 
minds to those things most worthy of worship, they adorned 
the temples, made god-like images and warlike weapons, raised 
monuments to their heroes and generally behaved themselves in a 
manner becoming the fortunate scions of the ever memorable 
and almost everlasting Bronze Age. 

Chapter III. — In the Middle Ages, the church being all- 
powerful and desiring to proclaim the fact for all time, inspired 
the now skillful bronze founders to invent some striking vessel 
which would yet speak when her ministers were dead. The bell- 



16 Practical Alloying 



founding feats of these patriarchs are beyond us today, and we 
have evidences in many parts of the world that they were no 
fool molders anyhow 1 

Chapter IV. — When the so-called civilization of the Western 
nations created that lust for empire, which still threatens to 
engulf us, those docile workers, now called brass founders, were 
requisitioned to produce an engine which would send the super- 
fluous savages occupying the desirable places of the earth, into 
"Kingdom Come." With characteristic ingenuity, befitting such 
highly developed craftsmen, they compounded a metal able to 
withstand the shock! Gun-metal, as you are aware, is used to 
this day — sometimes successfully. It has a name which is uni- 
versally admired and for that the public pay ungrudgingly the 
highest price. Some day an enthusiast from the ranks of the 
"Brassies," with a quicker imagination than I, may be inspired 
to write up more fully the historical side of brass founding. 
Meanwhile, we must get back to the more practical aspects of 
the subject. 

Definition of broyize. — The word bronze is of comparatively 
modern origin, being similar to the Italian bronzo, which is in 
all probability derived from bruno, signifying the brown color 
of the metal. While some of the ancient bronzes compare favor- 
ably with the later products of the metal industry, they invariably 
contain traces (sometimes even considerable percentages) of 
lead, nickel, silver, iron, and gold. It is inferred from many ex- 
amples of these early bronzes, that the ancients had not acquired 
the modern art of separating the individual metals — copper and 
tin — from the ores. The early smelters produced the bronzes by 
a judicious mixture of the ores, and were probably unaware of 
the impurities locked up in them. Ores are occasionally alloys, 
or combinations of the metals, and doubtless the earliest alloys 
used were reduced direct from the ores by the simple application 
of heat. The systematic study of the alloys was not begun until 
the latter half of the eighteenth century, but methods of tinning 
and gilding metals and the use of amalgams were known to the 
Romans. Bronze casting was also an important industry with 
them. Statues were erected in such numbers that they finally 
became a by-word. 



History and Peculiarities of Alloys 17 

According to Pliny, four varieties of Corinthian copper were 
made, all four being alloys of gold, silver and copper. The 
white variety contained an excess of silver, the red had an excess 
of gold. The third was a mixture of the three metals in equal 
proportions, and the fourth variety, hepatizon, derived its name 
from its having a liver color. It is a remarkable fact that metals 
seldom attain to their fullest usefulness in a state of purity. 
However desirable pure metals may be for some manufacturers, 
as dyes, drugs, or alloys of the precious metals, it is generally 
recognized that but little can be done with a metal until it has 
been combined with some other element. 

It would seem to be a law in nature that none of the ele- 
ments reach their greatest usefulness until they have been united 
with some other substance by mutual affinity. Water (fLO), 
air (O % + N %), salt (NaCl), and many other substances 
which minister to the support of life may be cited as compounds 
typical of the chemical energy which permeates the natural world. 
Nowhere is this power of attraction and chemical union more 
evident than in the mineral kingdom. The earth is full of com- 
pound substances ; and with all the accumulated science and tech- 
nical insight of modern philosophy, the last word has not been 
said on the condition and constitution of matter. And there are 
marvels in metals, just as truly as there are wonders in chemistry. 
In the sixteenth century, the "Gnomes" of Paracelsus, — sprites 
said to preside over the inner parts of the earth and to reveal its 
treasures — were invented as a foil to the inquisitive. Later, the 
"phlogiston" of the Alchemists furnished a convenient reason for 
chemical changes in the metals. 

Unexplained problems. — In the whirligig of time many such 
visionary, extravagant theories have been dissolved, but so far 
as alloys are concerned, there still remains a bewildering host of 
problems which cannot be explained by any available scientific 
rules. We have to acknowledge the existence of several allo- 
tropic conditions of metals and alloys which defy explanation. 
An alloy of platinum and iridium shows the remarkable property 
of being attacked by acids to which the pure metals are entirely 
indifferent. 



18 Practical Alloying 



It has not yet been demonstrated how the famous Mitis 
castings made from a mixture of wrought iron, cast iron and 
aluminum bronze, revert from the fibrous condition, back to their 
original strength and structure; or how two soft metals like tin 
and copper unite to form a flinty compound like bell metal or 
speculum; or how two malleable metals like gold and lead lose 
that property, immediately a trace of the alloy is introduced ; or 
how two stable metals like nickel and aluminum, in certain admix- 
tures, crumble into powder a few hours after they have been 
combined; or how aluminum should exert such a powerful in- 
fluence on the color of gold as to produce the remarkable white 
colored alloy (gold 90, aluminum 10) discovered by the late Prof. 
Roberts-Austen. Many other phenomena bearing on the rela- 
tions of the metals entering into combination as alloys, could be 
instanced. From recent experiments, M. Guillimane has shown 
that a ferro-nickel alloy, containing 25 per cent nickel, is almost 
as insensible to the action of a magnet as copper, notwithstanding 
the fact that iron and nickel are two of the substances most 
readily attracted by a magnet. 

A still more singular property appears in the discovery that 
the magnetic properties of the constituents may be conferred on 
the alloy by subjecting it to great and rapid cooling. Thus, we 
have an alloy, which, at ordinary temperatures is non-magnetic, 
but which becomes magnetic when cooled further. Advantage 
has been taken of this unique property of ferro-nickel alloys in 
the construction of some new scientific instruments and electrical 
appliances. But we must not make too much of the novelties 
presented by some alloys; the practical points of alloying are of 
more importance than the enumeration of metallic curiosities. 
The ordinary definition of an alloy teaches that it is a compound 
of metals obtained by fusion. 

Definition of alloy. — The alchemical usage of the verb alloy, 
meant, to temper one metal with another, the alloy always being 
the inferior metal, as copper in gold, or silver. This rendering 
still clings to us. Sterling silver is an alloy of 925 parts, by 
weight, of silver, combined with 75 parts of copper. In the 
language of the assaying office, the copper in this example is 
termed the alloy; but in a technical sense the metal resulting from 



History and Peculiarities of Alloys 19 

the combination of these proportions of silver and copper, in a 
liquid condition, is the alloy proper. Again, in brass foundry 
practice, the metals which are added to the molten copper to 
make an alloy — as lead and zinc in cock metal, or tin and zinc 
in gun metal mixtures, are termed the composition; but an ana- 
lyst would state the composition by the percentage of all the con- 
stituents contained in the alloy. Jewelers sometimes employ 
zinc in gold alloys ; it is generally used in the form of brass and 
is known by them as composition. Other examples of the misuse 
of the word alloy, are the well known trade terms, hardening, 
temper, etc. It is evident we begin to need a new definition of 
an alloy. The final product derived from the mutual solubility, 
or the fusion of two or more metals, is generally regarded as a 
perfect alloy. But some years ago the union of a metal with a 
non-metal was not recognized in that way. Cast iron has only 
recently been brought under this category, and many of the mod- 
ern alloys now manufactured as commercial specialties, do not 
come under the old description of perfect alloys. It has also been 
customary to regard all mixtures containing mercury as amal- 
gams ; but there are at least two alloys with a fair content of 
mercury, which cannot be so classed, namely, Dronier's malleable 
bronze, and Kingston's anti-friction metal. So that it would 
seem wiser to allow that the union of a metal with any other 
elements should be treated as an alloy, so long as the solidified 
mixture retains the essential characteristics of a metal. From 
a technical standpoint, the commercial value of the metals enter- 
ing into an alloy should not be taken into account at all. The 
fineness of gold is a relative term which might be as well ex- 
pressed by hardness, or any other quality. 

The importance of an alloy is not regulated by the price of its 
components as some erroneously imagine. The things that mat- 
ter are its chemical and physical properties and its suitability 
for the duty laid upon it. The presence of metalloids has a very 
decided influence on the structure, strength and solidity of metals 
and alloys. Sometimes it is a good influence, but not infrequent- 
ly it is for evil. The worker in alloys is therefore compelled to 
be more careful in his manipulations than the worker in metals 
which are not alloys. Besides being more difficult to tool and 



20 Practical Alloying 



less fit for wear and tear, unalloyed metals are, as a rule, not so 
well adapted for castings. Copper, nickel, and aluminum are 
very tenacious metals in the form of rolled sheets, rods, or tubes ; 
but if the same metals are reduced to the molten condition and 
poured into molds, the castings are generally disappointing, both 
in respect of solidity and tenacity. Heated to fusion, these 
metals absorb oxygen, and in cooling down to the solid condition 
they retain more or less of the dissolved gas, which produces a 
honeycombed structure. 

To overcome this defect, and to enable the founder to pro- 
cure homogeneous castings with these metals, Messrs. Cowles 
have advocated the addition of a small percentage of silicon in 
the case of copper; Dr. Flietman advised the use of magnesium 
with nickel; and in the case of aluminum, Dr. Richards has 
recommended an addition of zinc or copper. Comparatively few 
castings are made from unmixed metals nowadays. The prin- 
ciples of alloying are found to be so convenient and so advan- 
tageous, that with the exception of electrical appliances, better 
results may be achieved, and better mechanical properties may be 
imparted to the castings, if the mutual solubility of metals is 
regarded in the preparation of the metal to be cast. 

The art of alloying metals involves many principles, requir- 
ing much care and intelligence to attain the qualities desired in 
the finished product. Alloying has reference to the chemical 
relations of the metals and the methods of preparing and com- 
bining them ; but, with the exception of some few dual alloys, as 
alloys of copper-tin, copper-zinc, lead-tin, silver-copper, alu- 
minum-copper, etc., our knowledge of the effects of combining 
metals is far from being complete. Systematic researches have 
been confined chiefly to the copper alloys. Indeed, copper 
occupies much the same position in the industrial arena that gold 
has in the commercial world. It can be manipulated in more 
ways and with less uncertainty than any of the other metals. 
This is due to the wide range of properties copper is able to im- 
part to, or receive from other metals. The changes effected by 
alloying metals are generally more marked if there is considerable 
difference in the characteristics of the metals used. The alloy- 
ing of metals has generally a tendency to promote fusibility, 



History and Peculiarities of Alloys 21 

fluidity and hardness; and for the purposes of castings, the 
homogeneity of a metal is nearly always improved by the addi- 
tion of some other element. Color is also an important feature 
in alloys, but the coloring power of metals is more variable in 
alloys than in some other compounds employed for dyes and pig- 
ments. Ledebur arranges the useful metals in the following 
order: Tin, nickel, aluminum, manganese, iron, copper, zinc, 
lead, platinum, silver, gold. He says : "Each metal in this series 
has a greater decolorizing action than the metal following it. 
Thus the colors of the last members are concealed by compara- 
tively small amounts of the first members." The alloy used for 
nickel coinage affords a good example. This alloy is composed 
of copper 75 parts, and nickel, 25 parts ; the comparatively small 
quantity of nickel is, however, sufficient to completely hide the 
red color of the copper. But the color study of alloys has been 
pushed into the background by the more pressing need for purely 
mechanical effects, and variations in the physical properties of 
the metals are of first importance to engineers. 

Combinations of metals. — The nature of alloys has always 
been a matter of considerable controversy. Some of the metals 
combine in certain definite equivalents, terms atomic propor- 
tions, to form chemical compounds. Alloys of this description 
seem to possess superior qualities, and to be more stable than 
those produced by the haphazard admixture of metals in a liquid 
condition. Several metals may be dissolved in one another in 
all proportions, to form homogeneous alloys, while others refuse 
to be combined in any proportions which would qualify them to 
be classed amongst the useful alloys. When a mere mechanical 
mixture of metals is formed in an alloy, distinct crystals occur 
with one metal, between which the other is visible. Whereas, 
when an alloy is formed by the chemical combination of the 
metals, no such irregularities appear, and in some cases, the 
original equivalents cannot be destroyed by remelting. So that 
when two metals unite to form a chemical compound, we have a 
new substance with properties entirely different from the proper- 
ties of either of the elements which formed it, and because of the 
affinity or chemical attraction of the elements, it requires some 
superior power to separate the particles of this new combination. 



22 Practical Alloying 



It would be interesting to know if those metals which adhere 
well in electro-plating processes are, in any special sense, fitted 
to form true alloys. Electroplaters are aware that nickel adheres 
well to platinum, tin adheres well to copper, zinc adheres well to 
iron, gold adheres well to silver, mercury adheres well to tin. 
Is this due to chemical affinity, or does electricity contribute to 
the reciprocity? 

Again, some metals combine very readily with certain metal- 
loids, as iron with carbon; copper with silicon; nickel with 
arsenic ; aluminum with phosphorus ; lead with oxygen, etc. ; but 
by the introduction of a third element the chemical relationship 
of these combinations is disturbed. The inference to be drawn 
is that the union of a metal with a metalloid, even when they 
form a chemical compound, is more sensitive than a chemical 
compound of two metals. As a rule, a small addition of a third 
element in a simple alloy of two metals, helps to form a bond of 
union between them. For example, copper and iron combine 
with difficulty, but copper, zinc and iron produce many homo- 
geneous alloys of great tenacity. Again, nickel and aluminum 
make an unstable combination, but nickel, copper and aluminum 
give a series of remarkably tough and permanent alloys. Mer- 
cury and iron have no affinity for each other, but if tin is inter- 
mixed with these metals, an amalgam may readily be formed. 

The behavior of an alloy cannot be deduced ifrom the 
behavior of the components, neither does the apparent solution of 
one metal in another give any guarantee of homogeneous metal. 
It sometimes happens that certain proportions of the constituents 
in an alloy combine chemically, while others exist in a state of 
mixture or solution. The solidified mixture in such examples 
presents a mixed appearance in the fracture ; this is due to the 
different densities, fusibilities or chemical properties of the alloy- 
ing metals. Wherever there is a tendency to this condition, it 
may generally be aggravated by the slow cooling of the metal, 
or by raising the temperature of the molten alloy in excess of 
the heat required to render it fluid enough for castings. 

The character of many alloys is greatly modified by remelt- 
ing. Alloys containing tin or aluminum generally show an 



History and Peculiarities of Alloys 23 

increase of these metals after frequent fusions ; bells cast from 
metal which has been repeatedly remelted, acquire a disagreeable 
tone because of the formation and solution of oxides in the molten 
alloy; and alloys containing volatile metals, as zinc, arsenic, 
antimony, etc., may be rendered practically worthless by pro- 
longed melting. The presence of impurities in the metals used 
for making alloys is also a source of trouble; very small quan- 
tities of some elements seem to have far reaching effects on the 
properties of alloys. 

Dual alloys. — Naturally, the characteristics of dual alloys 
are easier maintained than combinations of three or more metals. 
Some of the most important alloys in the industrial arts, are 
unsophisticated combinations of two metals: Brass (Cu + Zn), 
bronze (Cu + Sn), nickel-silver (Cu + Ni), aluminum-bronze 
(Cu -J- Al), plumbers' solder (Pb + Sn), and standard gold 
(Au + Cu), and silver (Ag + Cu), are all dual alloys. Various 
additions have been made to these alloys with a view to improv- 
ing their mechanical properties, modifying their appearance, or 
reducing their cost, but the essential qualities of the alloy, in each 
case, can only be brought out by suitable proportions of the two 
metals indicated, being incorporated in the manufacture. Com- 
plex alloys are on the increase ; and subtle combinations are being 
devised to meet the wants of engineering and architecture. The 
alloys of the future will therefore require closer adherence to 
chemical principles, a better knowledge of the behavior of liquid 
metals, and some more scientific method of reduction than the 
open or reverberatory furnace. Delicate combinations demand 
delicate handling. This applies to alloys in particular, as they 
nearly always contain elements with weak affinities and are prone 
to oxidize, volatilize and deteriorate in the heat. 

This work, as I said at the beginning, was started with the 
object of throwing a few side-lights on the practical alloys and 
processes of brass founding. They may have been only dim, 
uncertain glimmerings, but brass founding being a dark subject, 
the smallest ray may be an illumination in itself. It has been 
my aim to show : 

First, that the discovery of bronze opened up the field for 
metal castings. 



24 Practical Alloying 



Second, that no castings have attained to the eminence of 
the bronze castings. 

Third, in order to become successful brass founders you 
should honor the traditions of the trade, the chief one being 
"Take care of the metals, the molds will take care of themselves," 
and be imbued with the belief that radium may come and steel 
may go, but bronze will continue forever. 



Ill 



THE PROPERTIES OF ALLOYS 

THE properties which contribute to the general usefulness 
of metals are hardness, tenacity, elasticity, malleability, 
ductility, density, fusibility, expansion by heat, resist- 
ance to corrosion and conductivity for heat and electrici- 
ty. These properties always show some variation from the mean 
when two or more of the metals are combined to make an alloy. 
In view of the great uncertainty as to the chemical condition and 
behavior of fused metals with one another, it would be impossible 
to lay down propositions covering the general results of alloying. 
Every new alloy is an experiment, because the manner in which a 
metal affects or is affected by metals with which it may be mixed, 
cannot be exhibited in advance. For the most part, the chemical 
properties of the metals are latent and the physical properties 
of the alloys depend upon the chemical conditions. 

Reasons for alloying metals. — Nearly all of the elements 
exist in a state of combination in nature, but for the uses of 
engineering it is necessary to separate and recombine the metals 
to produce alloys giving constructional advantages. The princi- 
pal objects of alloying metals are : 

To increase desirable qualities, as strength, hardness, tough- 
ness, or elasticity. 

To lower the melting point. 

To modify the color or structure. 

To facilitate the production of sound castings. 

To resist corrosion. 

To economize materials. 



26 Practical Alloying 



Hence, there is a growing tendency to group alloys by their 
predominant physical properties, as high-tension alloys, fusible 
metals, decorative alloys, deoxidized metals, non-corrosive alloys, 
and light alloys and anti-friction metals. 

Of the seventy-odd elements which have been isolated by 
the chemists, only some twenty possess properties of value in the 
production of commercial alloys. These are: Copper, zinc, tin, 
lead, antimony, aluminum, nickel, bismuth, cadmium, magnesium, 
iron, manganese, chromium, gold, silver, platinum, arsenic, phos- 
phorus, silicon, mercury. 

Carbon is an essential element in cast iron and steel and its 
alloys, but the conditions and effects of carbon in these metals 
and the use of the rare metals molybdenum, vanadium, titanium, 
etc., in the manufacture of special steels, are outside the scope 
of this work which purports to treat of the non-ferrous alloys in 
general use for castings. Besides, carbon is inert at the lower 
temperatures required for alloys in general. The great majority 
of the useful alloys are combinations of two or three metals, and 
the order in which the metals are stated above is approximately 
the order of their usefulness from the viewpoint of the foundry- 
man and the engineer. 

Two classes of alloys. — The alloys of a given metal may be 
divided into two classes : Those in which the metal is the chief 
constituent, and those in which it is present as a necessary con- 
stituent. For example, Tier's argent is an aluminum-silver alloy 
which is harder and easier worked and engraved than most other 
silver alloys. It consists of aluminum two parts and silver one 
part. On the other hand, aluminum bronze is an alloy of the 
second class, showing copper 90 to 97 parts of aluminum 3 to 10 
parts. But for the present we are more concerned with the phys- 
ical properties of alloys than with their composition. 

Hardness. — The property which is most generally conferred 
by alloying one metal with another is hardness. The hardness 



The Properties of Alloys 27 

of an alloy is very much affected by the rate of cooling as well 
as by the presence of impurities in the metals, but the relative 
hardness of the alloying metals gives no clue to the hardness or 
the fracture of the alloy. The following figures give the relative 
degrees of hardness for some metals and their alloys : Lead 7, 
tin 13, zinc 70, aluminum 89, copper 106, antimony 160, anti- 
monial lead 12, babbitt 18,. brass 164, hard bronze 244, phosphor 
bronze 253.* 

Mechanical treatment, such as /rolling, hammering, etc., 
hardens metals by changing the molecular condition, but when 
such metals are remelted they assume the normal hardness and 
structure on solidification. Nickel and manganese are the hardest 
metals entering into ordinary alloys ; but some comparatively 
soft metals have remarkable hardening powers, such as zinc in 
aluminum alloys, tin in copper alloys, or lead in gold alloys. 
The metalloids, arsenic, silicon and phosphorus, are also powerful 
hardeners. By combination in certain proportions with silicon, 
the hardness of steel is imparted to copper. With a greater or 
smaller quantity of silicon the properties of the alloy vary, the 
high silicon-copper being a capital deoxidizing agent, while the 
low silicon alloys possess great elasticity and power of resistance 
to heat, and they conduct electricity better than any other alloys. 

Another splendid example of the hardening effect of one 
element on another is seen in the modern alloy, "Meteorite," or 
phosphorus-aluminum, the phosphorus content not exceeding four 
per cent. In this case, as in most others, the increased hardness 
is not the only beneficial effect procured ; better casting and work- 
ing qualities accrue, and, speaking generally, crystallization is 
modified, the tensile strength is improved, sonorousness is in- 
creased, and a closer grain in the metal gives it a finer luster. 



*These figures refer to Baur's drill test for hardness and show the 
revolutions required to bore one-half inch of metal, using a ^-inch 
twist drills, the pressure on the drill being 160 pounds, and running at 350 
revolutions per minute. 



28 Practical Alloying 



Fusibility. — Another general result of alloying metals is to 
render them more fusible. With very few exceptions, the melt- 
ing points of alloys are below the mean of the metals used; 
sometimes they are even more fusible than the most fusible com- 
ponent, as for example, Wood's alloy, or any of the so-called fusi- 
ble alloys containing bismuth. The influence of heat on metals 
and alloys is a most interesting study. The extreme tempera- 
tures necessary in modern industries have developed a new field 
of metallurgy which promises to reveal many dark things con- 
cerning the resistance of refractories and the chemistry of high 
temperatures. None of the metals can resist heat or chemical 
action. The electric furnace is producing today many substances 
which offer enormous advantages over the products available 
at ordinary furnace temperatures. The immediate effects of 
heat upon metals and alloys vary considerably. Besides the dif- 
ference in the degrees of heat necessary to reduce them, the met- 
als show considerable difference in their behavior in the heat and 
cooling down to ordinary temperatures. Some of them soften or 
become pasty before actual fusion occurs, others pass directly 
from the solid to the fluid state and vice versa, while one, arsenic, 
passes when heated directly from the solid to the gaseous state 
without becoming liquid. It can only be liquified under pressure. 
All metals are volatile to a greater or less extent but the critical 
degree of heat at which some of them, as manganese, platinum 
and chromium, vaporize, is beyond the power of the ordinary 
furnace. 

Whenever there is a chemical union of the elements in an 
alloy, heat is liberated. Generally there is a marked increase in 
the temperature and also in the fluidity of the metal. The reac- 
tion of metals which melt at very high temperatures is not 
so easily controlled, therefore it is customary to make alloys 
requiring high temperatures by some intermediate process, say 
by reducing the oxides in the presence of some other substance 



The Properties of Alloys 29 



possessing affinity for oxygen. Similarly, for the union of 
metals which volatilize readily, as zinc or antimony, with metals 
requiring high temperatures for their fusion, as iron, or nickel, 
the direct method of mixing is always unsatisfactory. Fortu- 
nately, the chemical affinity of the metals admits of correct com- 
binations being made at temperatures slightly higher than are 
necessary to melt the less refractory metals. Thus, iron may 
be alloyed at the temperature of molten zinc. Copper may be 
dissolved in molten tin. Nickel is easily reduced in a bath of 
copper and platinum is attacked immediately when it is heated 
in contact with lead, or one of the metalloids, phosphorus, silicon 
or arsenic. These examples prove the common rule that alloys 
are more fusible than the fusibilities of the several metals would 
lead one to expect. 

To sum up, heat has a tendency to destroy cohesion; within 
certain limits it causes expansion proportional to the degree of 
heat; it lowers the tensile strength of most alloys and it affects 
the mechanical properties of different metals in different ways 
as evidenced by the various methods of working them in forging, 
welding, tempering, rolling, drawing, stamping, spinning, solder- 
ing and casting. Further, the action of gases on molten metals 
interferes with their molecular arrangement and hinders the for- 
mation of homogeneous alloys. At high temperatures the gases 
are more active and the metals are more easily permeated by 
them; it is always a wise precaution, therefore, to alloy the 
metals at as low heats as practicable. The alloy may afterwards 
be raised to the proper heat for casting, with better prospects 
of retaining the exact proportions and characteristics desired. 

Density. — The majority of the useful metals are between 
seven and eight times heavier than an equal bulk of water. 
Density, or specific gravity, is used as a term of comparison 
expressing the relative weights of equal volumes of different sub- 



30 Practical Alloying 



stances, and the metals are generally compared to the space 
occupied by 1 c. c. of water at degrees Cent. No body is per- 
fectly dense so as to have no interstices, or be destitute of pores, 
but the density of metallic substances may be considerably in- 
creased by mechanical treatment. The specific gravity of an 
alloy is sometimes greater and sometimes less than the mean of 
its components. When the density is increased, contraction has 
occurred, and chemical combination has probably taken place; 
but when the density is lessened, it shows that there has been a 
separation of the particles in the process of alloying, conditioning 
the expansion of volume. With the exception of bismuth, all 
metals are denser in the solid than the liquid state. As a rule, 
alloys are heavier than their calculated specific gravity, but a 
curious exception is the alloy containing aluminum, 18.87 per 
cent and antimony, 81.13 per cent. Its theoretical specific gravity 
is 5.225, which is the density it would have if its components 
combined with no contraction or expansion of volume. Its true 
specific gravity is 4.218. This shows a large expansion of volume 
during alloying which is clearly illustrated by the following fig- 
ures: 7.07 cubic centimeters of aluminum alloying with 12.07 
cubic centimeters of antimony, produce 23.71 cubic centimeters 
of alloy. This alloy is also an exception in the matter of fusi- 
bility. Antimony and aluminum both melt in the region of 600 
degrees Cent., yet the alloy does not melt below 1,080 degrees 
Cent. 

Working properties. — At this point we notice some of the 
working qualities of the metals and alloys. The leading charac- 
teristics of the metals are malleability, ductility and tenacity. The 
usefulness of metals and alloys depends to a great extent upon 
their classification, high or low, under these three headings. Of 
course, for castings, tenacity is always the most important prop- 
erty; cohesion is the first desideratum in cast pieces and a high 
tensile strength combined with toughness and elasticity ranks the 
metal or alloy well up in the list of useful structural materials. 



The Properties of Alloys 



The relative strengths and the toughness of some important 
copper alloys are graphically depicted in Fig. 1. 

EXTENSION IN FERCENTACE OF TOTAL LENGTH TESTED 





IO 20 30 




30 








~7 ! l l 


1 1 1 




























1 












3C 
26 






f 


M 


MCAI 


4E 


SE 


1 


2R 


OM 


ZE 




















V DELTA 


MET 


\L 








- 


















































































































































/ 
































































/ 
































































/ 
































































/ 










/\ 




















































J 


' 


























P 


-ic 


Gf 


>K 


OR 




BRONZE 
















































































20 


























































L 










20 
16 

to 

6 










.MILI 
































































































































































































































































\ 










/ 




























































/ 




















CI 


f N 


ft 


SE 1 


•£ 


. 






































































































































































15 






















BF 


!A 


5S 










































10 
6 






















































































































C 


:o) 


3 P 


ER 


































































































































































































































































































































































































































































































































































































































































































































































































































2 : 


) 





EXTENSION IN INCHES 

Fig. 1 — Relative strengths of copper alloys 



When metals are mixed together to form alloys, changes 
occur in the structure and physical properties of the product. 
Indeed, the modified properties of alloys are often of greater prac- 



32 Practical Alloying 



tical value than the independent use of the simple metals. The 
properties of alloys are widely different from the ratios of the 
combining metals, popper and lead are both highly malleable, 
but the alloy known as pot metal is not ; copper and tin are com- 
paratively soft, yet the alloys, bell metal and speculum, are harder 
than steel. The fluidity of zinc, melted in the presence of iron, 
is diminished, but its malleability is increased. Alloys of copper 
and zinc are more ductile than copper; alloys of aluminum and 
tin are less ductile than aluminum. From these examples it 
may be judged that the relative properties of the metals do not 
continue in their alloys. Further, given the properties of a defi- 
nite alloy, the effects of introducing even a trace of a foreign 
substance into it could not be foretold by any reasoning from 
analogy. 

As a rule, metals of similar character unite to form compara- 
tively weak alloys, and only where the constituent metals show 
great dissimilarity in properties do we get alloys that are united 
by the strong bonds of chemical affinity. 

Fracture. — The workability of metals and alloys depends 
largely upon their structure. Brittle metals show a feeble re- 
sistance to dynamic tests and they must be sparingly used in 
alloys that require to have good mechanical properties. Com- 
binations of antimony and bismuth, bismuth and zinc, or anti- 
mony and zinc, are on that account useless in the arts. 

The mechanical value of structure in metals may be illus- 
trated by the changes produced by increasing the content of a 
given metal in an alloy, zinc in copper for example. Beginning 
with pure copper we have the highly malleable and ductile quali- 
ties shown in the silky and finely fibrous fracture of the metal. 
By adding zinc up to 40 per cent, the metal assumes different 
structures at various stages. With 10 per cent zinc, the fracture 
is coarsely crystalline ; with 20 per cent it is finely fibrous ; at 30 



The Properties of Alloys 33 



per cent it is granular and it becomes more finely granular with 
additional increments up to 42 per cent. Meanwhile the tensile 
strength of the metal has steadily risen from 27,800 pounds to 
51,000 pounds per square inch. Beyond the 40 per cent limit, 
ductility, extensibility and strength decrease and at zinc 60 per 
cent, the fracture is vitreous conchoidal, with a tensile strength of 
only 3,727 pounds per square inch. Metallic fractures have been 
classified as : 

Crystalline . — Metals presenting this appearance are weak, as 
rupture occurs by the separation of adherent facets ; examples : 
antimony, zinc, bismuth. 

Granular. — This fracture resembles sandstone. The high 
tension alloys of modern times are all finely granular. The prin- 
cipal features of this structure are homogeneity, cohesion and 
flowing power. 

Fibrous. — The strongest and most readily worked of all 
metallic structures. Wrought iron is a good example of this 
fracture 

Conchoidal. — Metals possessing this fracture are hard, highly 
elastic and brittle, example, bell metal. 

Columnar. — This appearance is presented by some metals 
when they are broken hot. The metal has a tendency to separate 
in long fingers across the thickness of the ingot ; example, tin. 

It is a common occurrence to find two or even three kinds of 
fracture in a single specimen of an alloy like yellow brass, or 
German silver ; usually the granular and the fibrous, and the gran- 
ular and finely crystalline structures are associated with each 
other. 

Of course it is the aim of the founder to produce a metal 
of uniform structure, but metallography has revealed the fact that 
alloys, even when they are apparently homogeneous, present com- 
pound structures, and in many cases the direction in which the 



34 Practical Alloying 



different forms merge and settle contributes to their efficiency. 
Generally, the more rapidly a metal is cooled from the molten 
state the more regular the fracture when it is broken cold, the 
reason being that there is less time for impurities and segregating 
elements to gravitate toward the surface or the center of the 
mass. We do not recommend judging the value of metals, espe- 
cially alloys, by the fracture. It is well known that different 
treatments impart different properties to metals having the same 
composition. Fractures vary with the temperature and the man- 
ner in which the rupture has been produced. An ingot of yellow 
brass, broken between supports at 60 degrees Fahr., will present 
a granular appearance, while the same ingot, broken at 600 de- 
grees Fahr., exhibits a fibrous fracture, as No. 6, Fig. 2. Another 
example of a hot break is No. 2, the columnar structure, procured 
by heating an ingot of plumbers' soft solder and striking it sharply 
with a mallet. No. 3 is an aluminum-zinc alloy and the fracture 
is somewhat crystalline. The bronzes afford the best examples of 
granular fracture, No. 5, Fig. 2, and No. 7, Fig. 3, are manganese 
bronze and phosphor bronze, respectively. As showing the typ- 
ical fractures of copper-tin alloys with increasing proportions of 
tin, No. 8, Fig. 3, coarsely granular, is a sample of the standard 
gun metal (9 and 1 alloy) ; No. 4, Fig. 2, is a hard railway gun 
metal (7 and 1 alloy), and No. 1, Fig. 2, is a speculum alloy (2 
and 1 ) used as a hardening for babbitt metals. This fracture is 
highly conchoidal and the metal is brittle as glass and harder than 
steel. The tests which are sometimes made by gripping the metal 
on trial in a vise, and observing the angle through which it bends, 
or the number of blows required to break it, can only give the 
roughest idea of its capabilities. To get the true history and con- 
stitution of the metal, a closer examination and more accurate 
measurements are necessary. 

The two factors which determine the condition of alloys are 
their chemical composition and their physical structure. Chemis- 
try reveals the former and metallography, the science which has 
lately shed so much light on the microstructure of metals, inter- 
prets the condition and the limitations of the latter. 




Fig. 2 — Fractures of alloys 



?1 



.<; : ^ 




N 



Fig. 3 — Fractures of alloys 



The Properties of Alloys 35 

Conductivity. — All metals are good conductors of heat and 
electricity. Their relative conducting powers according to Mat- 
thieson, Franz and Weidemann, are given in Table I. 

Electrical conductivity is greatly diminished by a rise in 
temperature as well as by impurities in the metal. Alloys, as a 
rule, are very poor conductors and on this account the metals 
which occupy the lower positions in the following table are best 
suited for resistance coils, etc. The Cowles company prepares 

TABLE I 
Relative Conductivity of Metals p or 

For Heat Electricity 

Silver 1,000 1,000 

Copper 748 941 

Gold 548 730 

Aluminum 511 

Zinc 266 

Platinum 94 166 

Iron 101 155 

Nickel 120 

Tin 154 114 

Lead 79 76 

Bismuth 18 11 

a white alloy containing copper 67.5, zinc 13, manganese 18, alum- 
inum 1.20 and silicon 0.5, the electrical resistance of which is 
about 48 times that of copper and 37 times that of the standard 
German silver, considerably greater than that of any other mate- 
rial known which is capable of being drawn into strong, tough 
wire. 

The resistance of alloys is not affected by changes in the 
temperature to the same extent as the pure metals ; on the other 
hand, the purity of the metals, silver, copper, aluminum, etc., may 
be tested, and impurities detected by the diminished transmission 
of electric force. This is the latest tell-tale for adulterations or 
impurities in new metals. Owing to the presence of oxides, or 
to the fact that of their being melted in contact with the fuel cast 
metals, copper or aluminum, have not the high conductivity of 
electrolytically or chemically prepared metals. 

Peculiar properties of alloys. — Alloys generally have prop- 
erties differing in kind and degree from their constituents. Some 
metals alloy freely in all proportions and present few difficulties 



36 Practical Alloying 



in working, such as, silver and copper, copper and zinc, tin and 
lead. Others like lead and aluminum, or zinc and lead, cool out 
in layers. One cannot calculate the physical properties of an 
alloy from the physical qualities of the respective metals; small 
additions sometimes effect enormous changes. Alloys of brittle 
metals are always brittle, but the other qualities of metals do not 
continue in the same manner. The fracture is an index of the 
conditions of an alloy at the time of rupture, but the same alloy 
when remelted, may be unworkable, and when it is again ruptured 
the structure may be totally different owing to heat treatment. 

Alloys at critical temperatures. — A series of experiments 
conducted by Percy Longmuir, and embodied in a paper presented 
at the American Foundrymen's Association convention, in 1905, 
showed the remarkable variations in the properties of alloys, due 
to casting temperature. The behavior of the alloys was observed 
at certain critical temperatures and the results were summarized 
as follows : 

*High casting temperatures, Fig. 4, favor a large, ill-devel- 
oped type of crystallization, giving a characteristically loose type 
of structure. Fair casting heats, Fig. 5, favor a distinct but yet 
interlocked structure, and the crystal junctions are not so marked 
as is the case with the lower temperatures. Low casting tempera- 
tures, Fig. 6, give a most pronounced type of crystallization and 
the crystal junctions are very sharply defined, apparently forming 
routes along which fracture readily travels. 

High casting temperatures give a loose structure. 

Fair casting temperatures give an interlocked structure. 

Low casting temperatures give a sharp structure. 

The behavior of castings possessing these types of structure 
under steam or water test is as follows : Loose structures allow 
steam or water under pressure to ooze through the minute inter- 
stices of adjacent crystals. Interlocked structure effectually pre- 
vents any percolation of this kind, and the castings are there- 
fore tight within all pressures up to their limit of deformation. 
Sharp structures familiar to castings poured at a low heat will, 
if the crystal junctions favor, and they generally do, offer micro- 
scopical routes of penetration similar to those of high tempera- 
ture castings. 



*From the Proceedings of American Foundrymen's Association, 1905. 




"ig. 4 — Muntz metal poured at 

the "high" temperature 

(Magnified 200 diams.) 



*. 



Fig. 5 — Muntz metal poured at 

the "fair" temperature 

(Magnified 200 diams.) 



WfT^k 






\^f 




Fig. 6 — Muntz metal poured at the "low" 

temperature 

(Magnified 260 diams.) 



The Properties of Alloys 



37 



The accompanying tables reveal some of the remarkable ef- 
fects produced by slight variations in the casting temperature of 
typical alloys. 

A type of high quality steam metal in British practice is 
formed of copper 88 per cent, tin 10 per cent and zinc 2 per cent, 
and the results shown in Table II are characteristic of many 
experiments on this type of alloy. 

TABLE II 



Analysis 


Casting 
temperature, 
degrees Cent. 


Maximum 

stress, tons per 

square inch 


Elongation, 

per cent in 

2 inches 




s a 

D. u 

h. 


c 
c u 

H t. 


c 

C u 

N J; 

& 


Reduction 
of area, 
per cent 


87.5 


10.2 


1.8 


1173° 

1069° 

965° 


8.37 
14.83 
11.01 


5.5 

14.5 

5.0 


4.23 

16.71 

6.36 



A usual specification for castings of the foregoing alloy is a 
tensile strength of 14 tons per square inch, an elongation of not 
less than 7^4 per cent on 2 inches, whilst steam fittings must pass 
a water test of 1,700 pounds. Evidently the first and third cast- 
ings would hopelessly fail to meet such a specification; yet the 
three were poured from one 60-pound crucible, and the second 
one is separated from the first and third by the narrow time mar- 
gin of only two minutes on either side. 

Table III embodies results obtained from copper-zinc alloys. 

TABLE III 





Analysis 


Casting 

temperature, 
degrees Cent. 


Maximum 

stress, tons per 

square inch 


Elongation, 

per cent in 

2 inches 




loy 


Copper 


Zinc 


Reduction 
cf area, 
per cent 


Red 
Brass 


89.6 


10.2 


( 1308 
\ 1073 
( 1058 


6.85 

12.64 

5.67 


13.2 

26.0 

5.5 


12.65 

30. 2S 

6.64 


Yellow 
Brass 


73.0 


26.0 


( 1182 
■J 1020 
( 850 


11.48 

12.71 

7.44 


37.7 
43.0 
15.0 


31.40 
35.66 
15.25 


Muntz 
Metal 


58.6 


40.5 


( 1038 
\ 973 
( 943 


12.45 
1S.8S 
16.28 


6.0 

15.0 

9.5 


10.60 
16.10 
14.81 



The results obtained from the red brass alloy which is largely 
used as a brazing metal are of special moment, and it will be 
noted that a fall of 235 per cent in casting temperature doubles 
the mechanical properties, while a comparatively slight further 



38 Practical Alloying 



fall results in a very considerable lowering of these properties. 
The yellow brass results follow the same order, but here the 
fair casting heat appears to extend over a wider range, for the 
two first results are not greatly different. The third one, how- 
ever, speaks very powerfully as to the influence of a low casting 
temperature. The susceptibility of a high zinc alloy to variations 
in casting temperature is well shown in the Muntz metal results. 
Each of the foregoing alloys being constant in composition and 
every condition save that of casting temperature being identical, 
it necessarily follows that variations in mechanical properties are 
determined solely by variations of initial temperature. 

The crystalline structure of metals was discussed by Mr. 
Longmuir as follows : 

Crystallization begins in a number of centers and proceeds 
until the areas meet. This granular structure of pure metals 
seems to be quite universal. The crystalline elements in a grain 
are all ranged in the same direction or have the same orientation 
but the elements of two adjacent grains have different orienta- 
tion. The result of this is that when light is thrown obliquely on 
the surface of a pure metal, it appears to consist of light and 
dark grains, but these are all of the same kind, as may be proved 
by rotating a specimen, when the dark grains become light and the 
light ones become dark. 

Some metals, as soon as cast, are fibrous and uncrystalline, 
but become brittle and crystalline when heated and cooled, or 
hammered, or worked in any way. A high casting temperature 
conduces to the formation of large crystals with most alloys, 
hence it is desirable to pour the molten metal at a moderate or 
fair temperature, and make provision for cooling the castings as 
quickly as possible. This applies very particularly to anti-fric- 
tion metals. 

From the Cantor lectures by D. T. Kirke Rose, published in 
the Journal of Society of Arts, Nov. 15, 1901, we take the fol- 
lowing : 

Eutectic alloys. — Eutectic alloys have a number of charac- 
teristics in common. They have a lower melting point than that 
of any mixture containing their constituents in different propor- 
tions, and these constituents may be either elements or chemical 
compounds ; and they consist, not of a single solid solution, but 
of a mixture of two solid solutions. These two solutions sep- 
arate from each other only at the very moment of solidification of 
a single solution, and consequently the crystalline particles are 



The Properties of Alloys 39 

very small, and the structure minute. The separation of the 
eutectic may be effected by allowing a mixture to solidify partly, 
and then pouring or squeezing out the melted portion. 

The characteristic appearance under high magnifications is 
that of alternate bands of light and dark material. For example, 
the eutectic of iron and carbon is composed of curved bands of 
hard cementite standing out in relief, and of soft ferrite forming 
furrows between them. Mr. Stead points out, however, that 
the eutectics present themselves under many other forms. The 
eutectic of silver and lead isolated by Savile Shaw is found to 
consist of straight bands. Sometimes the bands are broken up 
into dots, the cellular structure, as in the case of the eutectic of 
phosphorus and iron containing 10.2 per cent phosphorus and 
89.8 per cent iron. When rapidly cooled, certain eutectics as- 
sume a spherulitic structure, as in the alloy of lead and antimony, 
containing 87.3 per cent lead and 12.7 per cent antimony. The 
two constituents begin to solidify from nuclei, and grow out- 
wards from these, yielding a mass with an appearance resem- 
bling that of certain minerals. 

When cooled slowly, some eutectics assume geometric crys- 
talline forms, which break up internally into the usually banded 
structure as in the triple alloy, containing 80 per cent lead, 15 per 
cent antimony, and 5 per cent tin. The eutectic alloy of anti- 
mony and copper, Fig. 7, by the different orientation of the alter- 
nate hard and soft plates in adjacent masses, also shows signs 
of the formation of large crystalline grains. 

Mr. Stead thinks it probable that the geometric forms are 
determined by the crystalline habit of the hard constituent, and 
further research is needed to determine whether there is any 
disposition on the part of the homogeneous liquid solution to 
crystallize as a whole, a disposition which is instantly modified as 
solidification takes place, and the solution breaks up into two 
solid solutions. 

There is, at any rate, no essential reason apparent why the 
structure, of eutectics should be so exceedingly fine ground. Per- 
haps by heating eutectics to a little below their melting points f or 
long periods of time, the constituents may be more completely 
separated, and studied with greater convenience. 

The study of alloys with the aid of the microscope has made 
rapid advances in recent years. Fig. 8 is an anti-friction alloy 
containing 83.3 per cent of tin, 11.1 per cent of antimony and 
5.5 per cent of copper. The load is carried by the hard grains 
which have a low coefficient of friction and are not easily sub- 
ject to the accidents known as hot-box and cutting when there is 



40 Practical Alloying 



an abrupt and very great increase in the coefficient of friction. 
When an axle is placed in a new bearing, however, contact be- 
tween the two takes place only in a small number of points, and 
if both axle and bearing are hard and unyielding, heating rapidly 
ensues. To avoid this and to allow for irregular wear, and also 
for irregularities of adjustment in erecting a shaft carried by 
several bearings, the matrix of the anti-friction alloy must be 
soft and plastic so as to mold itself to the axle during the run- 
ning, and yet must be strong enough to carry the load without 
permanent distortion. 

It is well to add that Behrens and Baucke* do not agree 
with Charpy. They find the star-like crystals are too brittle to 
stand much pressure and crumble badly. If, however, the metal 
is cast at a proper temperature, the fragments worn off are 
largely spheroids in shape, consisting of worn cubes of the anti- 
mony-tin alloy, and these mixing with the oil form a ball cushion, 
so that a rolling instead of a sliding friction is set up. 

Surfaces of fusibility. — Lead and antimony form alloys 
suitable for the bearings of axles, but in general binary alloys 
are not suitable, and ternary, or even more complex mixtures 
are employed. In studying these, M. Charpy showed that just 
as the constitution of binary alloys can be deduced from their 
curves of fusibility, so that of ternary alloys can be ascertained 
by the construction of surfaces of fusibility. 

Thus, in Fig. 9, the points, A, B, C, are the apices of an 
equilateral triangle, and any point, M, inside the triangle corre- 
sponds to a particular ternary alloy, the distances from the three 
sides, the sum of which is constant, representing the proportions 
of the three metals. If, now, a line is raised from the point, M, 
perpendicular to the plane of the triangle, and its height made 
proportional to the temperature of fusion of the alloy, and the 
same procedure is followed for all points inside the triangle, sur- 
faces of fusibility are traced out resembling that shown in Fig. 10. 



*Metallographist, January, 1900, page 4. 



„\iS> V, 



uW^ 



N« 



U* 




Fig. 7 — Eutectic alloys of antimony Fig. 8 — Alloys of tin, antimony and 
and copper copper, polished and etched 





Fig. 9 — Constitution of ternary alloys 



Fig. 10 — Surface of fusibili 
ty of ternary alloys 



IV 



SOME DIFFICULTIES OF ALLOYING 



THE difficulties in the way of making alloys are many and 
real. The common difficulties attending most manufac- 
turing processes may generally be overcome by diligent 
application and the observance of well known laws and 
conditions, but the combining of metals to form alloys cannot 
always be regulated by the normal behavior of the individual com- 
ponents. Some knowledge of chemistry and the chemical rela- 
tions of the elements is absolutely essential to the intelligent 
handling and treatment of the metals throughout the various 
stages of manufacture into alloys. But the modern tendency in 
all manufactures is to reduce the chemistry of the processes 
to the simplest form so as to make it easy for the unskilled 
worker to produce correct combinations. In photography, the 
amateur has at his command a large selection of compressed 
reagents enabling him to obtain results which for lack of 
technical knowledge or on account of the expense, he could 
not otherwise reach. In medicine, too, the physician, by 
means of tablets is able to relieve his patient of much of that 
nausea following the use of liquid drugs. And in the metal 
world the principle of preparing concentrated alloys of metals 
which, subjected to the ordinary treatment, unite with difficulty, 
has grown within the last twenty years to be a specialized in- 
dustry, making it possible for the general founder in alloys to 
produce economical and reliable combinations of volatile and 
highly refractory metals. 

Alloying by concentrates. — These "tabloid" alloys, if we may 
so name them, have been a great boon to foundrymen. We all 



42 Practical Alloying 



know the danger and uncertainty attending the direct introduc- 
tion of phosphorus, mercury, magnesium or aluminum, into molt- 
en metals at high temperatures. The brass founder has benefited 
greatly by this new system of alloying by concentrates. Copper- 
manganese, ferro-zinc, aluminized-zinc, phosphor-copper, phos- 
phor-aluminum, phosphor-tin and silicon-copper, in guaranteed 
proportions, are easily procurable by the foundryman, and they 
are quite as convenient as prepared reagents are to the practical 
chemist. Indeed, practical alloying in its modern aspects may 
justly be described as a higher branch of practical chemistry, 
where crucibles and furnaces take the place of beakers and Bun- 
sen burners, gases and liquid metals act and react, and the result- 
ing compounds follow unchangeable laws with the same accuracy 
as we find in laboratory practice. 

The reactions of metals on metals in the molten condition are 
quite as consistent as the reactions of other substances, but up till 
now they have not been classified. 

Metallurgists have been too busy grappling with problems 
arising out of the physical conditions and relations of the metals 
to exhibit the chemistry of alloys with anything like fullness. 
Nevertheless, the subject of metallic reactions is one deserving 
of the fullest investigation. If foundrymen in their everyday 
experience have had it demonstrated that the presence of man- 
ganese tends to precipitate sulphur in cast iron, the presence of 
aluminum tends to precipitate lead in brass, the presence of 
antimony tends to precipitate copper in silver alloys, and addi- 
tional copper tends to precipitate lead in pot metal mixtures, 
surely an extended list of such reactions would mark the danger 
line in certain mixtures and help the founder in alloys to a better 
and more scientific method. 

We can understand then how it is that the method of making 
an alloy is sometimes rather a vexed question. Recently, much 
light has been thrown upon the structure of metals, as the follow- 
ing indicates : 

It has been shown, for example, that iron and other metals 
may exist in several distinct (allotropic) forms. In general, all 
crystalline substances have a non-crystalline form, and the phys- 



Some Difficulties of Alloying 43 

ical properties of the two are usually very unlike. Tenacity is 
greatly increased by drawing into wire. In the case of soft 
iron resistance to stretching is thus increased from 20 to 80 tons 
per square inch. The resistance of gold when drawn into wire 
increases from 4^ to 14 tons. Silver and copper show an even 
more marked increase. Until recently, the adjective crystalline 
suggested hardness and brittleness ; but in the pure ductile metals 
it has been shown that the crystalline state is actually the soft 
state. The softness of these metals is in fact due to the instabili- 
ty of the crystalline formation. The non-crystalline state is the 
more stable mechanically, and therefore the harder. When a 
metal is hammered to some extent the crystalline structure is 
broken down, and thus the hardness is increased. The process, 
however, is never complete. Even in gold leaf beaten to a 
thickness of 280,000th of an inch there are still minute crystalline 
units which escape destruction because they are protected by the 
harder, non-crystalline portions in which they are embedded. 
Hence, hardened metals are always complex mixtures of crystal- 
line and non - crystalline structures. In the passage from the 
crystalline to the non-crystalline state there is an intermediate 
condition in which the molecules appear to have much of the 
freedom and mobility of the liquid state. If this is suddenly 
congealed no crystals are formed. The same thing happens in 
the case of an ordinary liquid when suddenly frozen. A curious 
evidence of the complex nature of a pure metal due to the pres- 
ence of distinct allotropes of the element, is the fact that wires 
of hard and soft pure metal act together like a thermo-electric 
couple of two distinct metals. Another curious fact is that it is 
not necessary to melt a hardened metal to get it back into the 
crystalline form. This is restored at far below the melting point. 
Thus gold again becomes crystalline if heated to 280 degrees 
Cent., while it does not melt much below 1080 degrees Cent. All 
that is required is to add just enough kinetic energy to the mole- 
cules to enable these to overcome their cohesion ; as soon as they 
can do this, they arrange themselves in the definite form char- 
acteristic of their crystals. 

In alloying, the chemical qualities of the metals are of the 
very first importance ; and still the general approach to the prac- 
tical combination of metals is made by experiment and deductions 
from physical tests. It is here the difficulties in alloying metals 
begin. We make utility the supreme test of a metal and all our 
standard metals are the product of extended experiments. These 
standards are liable to be displaced by later experiments, ancj the 



44 Practical Alloying 



discovery of new methods of combining the metals. In every 
case the excellence of the later product might have been attained 
through a closer study of the chemistry of the alloying metals. 

Alloys in bronze. — The improvements in bronze due to the 
introduction of chemical equivalents of phosphorus, manganese, 
etc., and the superiority of sterro-metal based on the chemical 
affinity of zinc and iron, afford striking proofs of the advantages 
of chemical as opposed to the mechanical solution and combining 
of metals. Of course, in ordinary melting practice, there is 
always a tendency for the metals in an alloy to cool out according 
to their specific gravities, and if there is much difference in their 
melting temperatures, the more fusible metal is apt to liquate 
after the principal alloy has set. Exceptions, be it noted, are 
metals which enter into chemical union, or metals which may be 
freely mixed in all proportions showing always the qualities of 
a true mixture by the predominance of the physical properties of 
the metal present in excess. Common examples of the latter are : 
Copper-zinc alloys, aluminum-zinc alloys, lead-tin alloys, and 
silver-copper alloys. Such metals present few difficulties in work- 
ing and perfect casting alloys may be obtained by the direct 
method, i. e., the more infusible metal is melted first and the 
desired proportion of the more fusible metal is dissolved therein. 

Metals which are liable to liquate out of an alloy require to 
be constantly stirred while liquid and to insure sound castings 
they should be remelted, cast at a low temperature and cooled as 
quickly as possible. 

Alloys for castings are only of service when the metals enter- 
ing into the composition can be made to unite and form homo- 
geneous compounds. It follows, therefore, that the first aim of 
the workman in making alloys is to unite the metals in such a 
way that the finished product will retain all the characteristics of 
a true metal. Many metallic compounds that we know of are 
utterly useless for any of the purposes of a metal. That the 
metals have stronger affinities for the non-metallic elements than 
for other metals is amply proved by the condition of the majority 
or the ores from which they are derived. In nature, free metals 
are the exception. All metals combine with oxygen, sulphur and 



Some Difficulties of Alloying 45 

certain radicals in proportions, which to a great extent are deter- 
mined by the temperature and their environments. 

Oxidation of metals. — Oxidation is the chief hindrance to 
the perfect union of metals as alloys, and oxides are the bane of 
metal mixers. As a rule, the activity of oxygen in combination 
with fused metals increases with the temperature and also with 
every additional element present in the alloy. Complex alloys are 
therefore not so easily manipulated as alloys of two, or perhaps 
three metals. 

The mere surface oxidation of metals is not nearly so harm- 
ful as the formation of oxides by metallic reactions, some of 
which have already been noted. 

When the oxides of the constituent metals dissolve in an 
alloy, or rather, are carried in solution, the resulting metal is 
always materially decreased in strength, tenacity and homo- 
geneity. The usual precautions against oxidation are not equal to 
the prevention of a certain loss in melting, but by special treat- 
ment, alloys may be prepared free from oxides. 

Difficulties of alloying. — The liberal use of suitable fluxes 
and materials to exclude the access of air is practiced in every 
brass foundry ; and in some cases special precautions are taken 
to preserve a deoxidizing flame within the furnace. The choice 
of fluxes for alloys and the part they play in removing impurities 
and in reviving the fluidity and other properties of the metals, 
constitutes an important branch of the business of practical alloy- 
ing, — a branch which demands close reasoning and discernment of 
the chemistry and the physics of materials. That being so we 
shall do well to devote a separate chapter to foundry fluxes and 
their effects. But to return to our difficulties. The shrinkage 
of alloys and their habits of congealing give the brass founder 
more pause than the mere reduction and blending of the metals. 

The rate of melting, the temperature of casting and the rate 
of cooling are three very important factors in determining the 
density, grain and soundness of alloys. No metal can be melted 
without decomposition but the ultimate composition and the 
physical qualities may be controlled within well known limits. 
Foundrymen are well aware that some alloys are stronger than 



46 Practical Alloying 



others, even when chemical analyses proves them to be identical 
in composition. This should draw attention to the fact that alloys 
are extremely sensitive to heat treatment. The effect of high 
temperatures on metals of low fusibility is always harmful, favor- 
ing the absorption of gases, the formation of oxides and ine- 
quality of the properties usually associated therewith. It is a 
common delusion that the metals in an alloy should be melted hot 
to insure a thorough mixture ; it is also a common mistake of 
some molders to demand hot metal for all kinds of castings. The 
tyro at mixing alloys frequently blunders because he does not 
understand the delicate nature of forces nor the susceptibilities of 
materials in an atmosphere of 2,000 degrees Fahr., or thereabouts. 
He regards heat as the influence to which all metals must suc- 
cumb ; and he does not seem to be aware that many of the metals 
may be more easily dissolved in, and more safely and perfectly 
combined with other metals at lower temperatures than the melt- 
ing point of the most refractory in the series. 

Combustion of the metals is useful in certain refining proc- 
esses but it is altogether an undesirable incident in alloying. To 
alloy metals properly one requires to be more than a diligent fire- 
man. For every alloy there is a proper heat beyond which it 
should not be raised, and a casting temperature at which the best 
results are to be obtained. Proper heats and castings tempera- 
tures will some day be standardized and included in the specifica- 
tions for standard alloys, but it is never safe to predict finality 
in the methods of their preparation. 

It is an axiom in the metal trades that the most refractory 
component in an alloy should be first reduced to form a bath in 
which the more fusible metals may be dissolved. This custom 
dies hard, nevertheless it is doomed. The introduction of inter- 
mediate alloys, as ferro-zinc in delta metal, hardening in babbitt 
metals, and copper-manganese in manganese bronzes, has changed 
the general practice of combining metals by their solubilities to 
the more effective chemical methods of modern times. 

The most widely diffused metals are not necessarily the most 
easily reduced or alloyed. Aluminum has always been plentiful 
but it is only beginning to be a profitable product; iron also is 



Some Difficulties of Alloying 47 

plentiful, but it must be used sparingly in alloys. Many of the 
metals do not make practical combinations by the ordinary 
methods of alloying, while others are favorably influenced by the 
introduction of another element. It sometimes happens that the 
addition of a third element favors the union of two non-combining 
metals, thus — 



Cu \ / Fe = Delta Metal 



Zn 
Cu 



I Ni _ 

\ / = Romanium 



M<s 1 
^ / 
Zn 



Again, goldsmiths use gold alloyed with copper and silver 
in preference to the copper hardened or silver hardened metal. 
The three metals combine to form tough, malleable and ductile 
alloys of better working qualities than those obtained by using 
copper or silver alone, as the alloying metal. Copper and lead 
have a very weak affinity for each other, but alloys of copper and 
lead are rendered more homogeneous when nickel is added. 

Remelting Alloys. — Fortunately, the difficulties arising from 
impurities in the metals are lessening and today it is not nearly so 
needful for most requirements if only a portion is remelted. 
Of course we have to admit that any treatment of a metal which 
increases its density usually increases the strength also. But as 
most metals lose in fluidity every time they are remelted, it is 
recognized that melting a portion of the new metals with the 
already mixed alloy is advantageous. Some alloys are less fluid 
at higher temperatures than they are at a moderate heat above the 
melting point. Aluminum alloys and anti-friction alloys of zinc, 
copper and tin behave in this way ; they are easily overheated and 
much waste results from careless melting. The microscopical 
examination of alloys has confirmed the belief that the tempera- 



48 Practical Alloying 



ture and melting conditions exert considerable influence on the 
permeability of the metals. Metals which appeared to be saturated 
with some particular alloy have, by changes of temperature and 
melting methods, been made capable of taking up more of the 
alloy. The variations in the molecular condition of different 
specimens of the same alloy, are also largely due to variations 
with melting practice. We have already said metals are now 
obtainable in comparatively high conditions of purity, but it is not 
always easy to keep them so, particularly when their fusibilities 
are unyielding. 

The higher the temperature at which a metal becomes fluid 
the more readily does it occlude gases and absorb impurities; 
hence the difficulties of alloying increase with the temperature 
required to reduce and combine the metals. In Cowles' electrical 
method of producing aluminum bronze, it is assumed that the 
aluminum and copper unite when both are in the gaseous condi- 
tion, and by this means "a completeness of union between the 
constituents of the alloy is obtained, superior to alloys formed in 
any other way." Here is a method of alloying which awaits 
development. All metals may be heated until they assume a 
gaseous condition, but only the records of the patents office reveal 
to us examples of metallic combinations of this unique order. 

The modern practice in alloying metals which are difficult to 
unite by direct method is to present one of the metals in a nascent 
condition. For example, Dr. Goldschmidt's process of alloying 
tungsten with aluminum for the production of wolframinium is 
accomplished by adding tungstic oxide to the reducing bath in the 
manufacture of aluminum. Again, to alloy nickel with aluminum 
is not an easy matter ; rich alloys of the two metals are generally 
made by adding NiO to a bath of Al. 

Up to the present, we can alloy metals of every class and 
enhance such desirable properties as color, strength, sonorous- 
ness, flexibility, etc., but not by rule or rotation. Anomalies occur 
in the practical processes of alloying which demand special treat- 
ment. 

The properties of the various metals undergo such diverse 
changes in the heat and they are so easily influenced by the pres- 



Some Difficulties of Alloying 49 

ence of minute proportions of other bodies that no hard and fast 
rules can be given for combining them into alloys. 

Physical characteristics of alloys. — The iron founder has 
only to study the fluid characteristics of cast iron, and with ordi- 
nary skill in molding he should secure good castings. It is differ- 
ent with the founder in alloys, he strikes new features with every 
change or addition in the metals. Due to long experience, and 
the mutual affinity of the metals forming the alloy — brass may be 
cast with reasonable prospects of good results in the castings; 
but add another element to it — iron, manganese, aluminum, nickel 
— and the new combination defies the old experience. Gates, 
ramming, sand, venting and melting methods all require modifica- 
tion. 

In short, the physical properties of alloys depend upon their 
chemical composition and also upon the treatments, thermal and 
mechanical, which they undergo; so that, to possess the correct 
formula for an alloy and not to know the correct treatment for 
the combining metals is like trying to solve a puzzle without the 
key. 

The chemistry of high temperatures and the reactions of 
metals are at the root of all the changes and troublesome modifi- 
cations encountered in practical alloying. When this side of 
metallurgic endeavor is better delineated and better understood, 
the practical difficulties of alloying will be greatly minimized, at 
least, so far as alloying with new metals is concerned. 

Grading by fracture. — Unfortunately there is a growing prac- 
tice in the various kinds of metal foundries of using mixed metals 
to produce standard alloys economically. The purchase of these 
mixed metals or scrap alloys by specification is too ideal for pres- 
ent day consideration, so grading by fracture and color is adopted. 
It has been borne in upon iron founders that grading by fracture 
is a lottery; by and by the same idea will penetrate to the brass 
foundries, the type foundries and the so-called metal refineries. 
It is admitted that some outlet must be found for old metals, but 
the miscellaneous scrap heaps of the junk dealer grow more 
treacherous every year; the values are often fictitious, and noth- 
ing short of a remelt and analysis should satisfy anyone desiring 
to be honest in building up alloys from scrap and mixed metals. 



50 Practical Alloying 



I was once called upon to find a use for about four tons of 
mixed babbitt and anti-friction metals collected by my predeces- 
sors from ships and engines undergoing repairs. With difficulty 
I persuaded the management to stand the expense of melting 
down the lot into ingots. Drillings were taken from each ingot 
and again the drillings were melted for analysis. This showed: 

Per Cent 

Tin 55.69 

Lead 32.04 

Antimon}' 8.65 

Copper 1.95 

Iron 0.18 

Zinc 1.13 



99.91 



Now it should be evident to anyone acquainted with anti- 
friction metals that this mixture could only have a limited appli- 
cation. By the judicious addition of tin, copper and antimony, a 
good serviceable bearing metal was produced, and the economy 
was so great in this instance that the firm afterwards adopted 
the same method of dealing with brass and gun metal scrap and 
castings left on their hands by customers. They found it paid 
better to know just exactly what they were putting into the daily 
mix. In dealing with old metals an analysis gives the like 
assistance to the metal mixer that a chart gives to the mariner. 

James A. Darling, Philadelphia, claims to have discovered 
a process for making alloys of copper and iron which are per- 
fectly homogeneous. This process consists in melting copper with 
a mixture of oxide of iron and calcium carbide, which gives, after 
being properly treated, the above mentioned alloy. Any oxide of 
iron, either hematite or the black oxide, can be used. A 
mixture of three parts of oxide of iron and one part of calcium 
carbide is made, and, if it is desired to obtain a 50 per cent alloy 
of copper and iron, 18 parts of this mixture should be used to 8 
parts of copper. The copper is melted in a crucible and the mix- 
ture added, a little at a time, the bath being stirred and the tem- 
perature raised gradually. When the operation is completed, the 
alloy is poured in ingots or any other desired form. 



Some Difficulties of Alloying 51 

If an alloy containing as much as 85 per cent of iron is 
required, the process is reversed, a bath of iron being substituted 
for the bath of copper, and a mixture of oxide of copper and 
calcium carbide being added. The inventor claims that, on ac- 
count of the fact that one of the metals is presented to the other 
in a nascent condition, a perfect union is formed. 

This is an example of making alloys by laboratory methods. 
For experimental work such methods have their place, but the 
practical difficulties have still to be met and grappled with by 
practical means. 



V 



METHODS OF MAKING ALLOYS 



THE importance of method in making alloys can hardly be 
overestimated. Perhaps there is no industry requiring 
more constant, vigilance, or more careful revision at the 
different stages of manufacture, than the production of 
the metallic alloys. Practical metallurgy is concerned with the 
smelting, refining, and alloying of the metals ; these three proc- 
esses are frequently interdependent, but the climax is reached 
in the last named, as the behavior of alloys rarely coincides with 
the behavior of the component metals. Owing to the many 
valuable properties which certain proportions of the useful 
metals impart to each other, the manufacture of alloys and the 
desire for new combinations is not likely to diminish. The 
advantages to be gained by alloying metals are not con- 
fined to any particular branch of metal working, but as 
the majority of the useful alloys are handled by the brass 
founders, and we are at present more intimately concerned with 
the founding of metals, our survey of the manufacturing methods 
shall follow the routine of the foundries. The methods of prepar- 
ing alloys now in vogue have been developed within the last 50 
years from crude and unreliable forms of procedure into more 
systematic standards. Nevertheless there is no code of rules for 
the correct production of alloys. There can be none since the 
different alloys have to be made, with necessary changes, accord- 
ing to the nature and characteristics of the metals employed. All 
the metals possess much the same characteristics but in such 
widely varying degrees that the treatment meted out to those at 



Methods of Making Alloys 



one end of the scale, would be altogether unsuitable for those at 
the other end. The nature of an alloy cannot be determined be- 
forehand from our knowledge of the metals. 

Metals in the fluid condition obey the laws of fluids. They 
have a solvent power which generally increases with the temper- 
ature, but which is not limited by the fusibility of a solid metal in 
conjunction therewith. When a molten metal has been saturated 
with another metal, its power of dissolving the latter may be in- 
creased by the addition of a third constituent. When a solid dis- 
solves in a liquid there is a change of temperature due to chemical 
changes effected by the molecular motions of the two bodies. 
Thus, in making alloys, heat is sometimes absorbed, but in most 
cases the reaction is exothermal, heat being evolved. Metals 
which combine with the liberation of heat are in particular well 
suited for forming alloys. 

Alloys may be prepared mechanically by compressing the 
powders of the metals, and electrically, by depositing the metals 
by means of a powerful electric current, but the most important 
method of alloying is by the direct fusion of the metals in a 
heated atmosphere. 

Most metals are capable of existing in some degree of chem- 
ical combination with each other, but we know so little of the real 
nature of chemical affinity that alloys are generally composed 
experimentally, as mixtures without any special regard to chem- 
ical principles. As it has already been shown, alloys were made at 
first quite unconsciously by the early metal refiners. Aurichal- 
cum, i. e., golden copper, was a product of nature, and the secret 
of its manufacture could never be mislaid. Brass was originally 
manufactured by the cementation of calamine (ZnCOs) and 
copper, long before the discovery of zinc in the metallic form. 
The ancient Greeks acquired such proficiency in preparing this 
alloy that the demand for Corinthian brass was greatly increased. 

Alloying by the Ancients. — But the alchemists were the orig- 
inators of systematic experiments in the art of alloying; and as 
they generally dealt with small quantities of the elements they 
were studying, it was easy for them to fuse the various metals in 
separate crucibles and bring them together by pouring them into 



54 Practical Alloying 



one another. This was the first practical plan adopted by metal- 
lurgists for the manufacture of alloys ; but as the number of met- 
als entering into alloys increased, it was found more convenient 
to make a preliminary combination of two or more of the com- 
ponents, and to dissolve that in the metal forming the base of the 
alloy. We have a survival of this method in the manufacture of 
anti-friction alloys, hardening, in this case, being the name of the 
preliminary alloy. Bell founders make an alloy of copper and 
tin in equal proportions, called temper, and this is used to harden 
the copper, and to avoid remelting the whole of the alloy. Brass 
founders sometimes prepare a mixing metal to be used in making 
up alloys to a required standard. Delta metal is prepared by 
adding zinc which has been saturated with iron, to molten cop- 
per; and phosphor bronze, to be correctly made, requires a pre- 
liminary combination of phosphorus and tin, or phosphorus and 
copper. These are a few examples of the direct fusion methods 
of making alloys. 

Like many other industries, the manufacture of alloys has 
been surrounded with a great amount of secrecy. The results of 
alloying processes have been well advertised, — but the processes 
themselves — not much. 

It would seem as if the public needed to be impressed with 
the unique qualities and trade marks of certain alloys — and patent 
medicines. It is quite true that the exact composition and the 
mode of preparation are important matters in producing uniform 
alloys, and while we may by chemical analysis, be able to deter- 
mine the exact composition of an alloy, it may not be possible, by 
ordinary methods, to reproduce the physical properties of the 
original sample. Many celebrated metals owe their inherent 
virtues to a particular mode of manufacture. Alloys are sensi- 
tive compounds ; as a rule they are more easily oxidized than their 
components, and remelting makes a remarkable difference in their 
physical conditions. Generally, the proportions of the constit- 
uents are changed thus : Alloys containing aluminum, copper 
and iron, show an increase when remelted, alloys containing zinc, 
tin, manganese, phosphorus, antimony and bismuth, show a de- 



Methods of Making Alloys 55 

crease when remelted ; alloys containing lead remain stationary 
when remelted. The difficulty of preparing alloys of definite 
composition is increased when old metals are combined with new 
to make an alloy. It is quite possible to build up alloys to any 
specified standard with scrap or remelted metals, provided the 
average content of the components is known. But it should al- 
ways be borne in mind that the chemical analysis of an alloy 
gives no information as to the method of its production, and the 
properties of an alloy cannot always be reproduced simply by 
using the published formula. 

The actual capabilities of a metal are seen in the physical 
tests, and as it is easier to keep to the chemical proportions than 
to combine the elements in the same physical condition, the best 
results are obtained by preventing liquidation, oxidation, crystal- 
lization, or anything that would interfere with the homogeneity of 
the alloy. In making sound castings from almost any of the 
alloys, the metal should not be overheated, and as a general rule, 
it should be poured when it is sufficiently fluid for the work. 

Melting alloys. — Prolonged melting is to be avoided except 
where the removal of volatile impurities is desirable. Antimony, 
arsenic, zinc, mercury and bismuth are sometimes removed from 
alloys by keeping them in a molten state for a prolonged period. 
Alloys are always more fusible than the mean of their constit- 
uents, and their physical properties and chemical behavior alter 
with every fresh addition. Metals with weak affinity generally 
show the characteristics of the metal present in largest quantity, 
and vice versa. 

It often happens that two competing firms make castings 
from the same patterns and to the same specification. Both lots 
analyze within the limits of the specification, but when the cast- 
ings are put to the physical tests there may be a difference of a 
ton in the tensile strength or 100 pounds per square inch in 
hydraulic resistance — all the difference between good and bad 
castings — in the two lots. This can only be accounted for by the 
methods of selecting, melting, mixing and casting the metals. It 
has been understood for a long time now that the presence of a 



56 Practical Alloying 



small, nay, almost insignificant quantity of an element may have 
a far-reaching influence on the properties of a metal or alloy. 

Aluminum cannot be used in the highest quality of steel as it 
induces crystallization. Magnesium, like aluminum, is a power- 
ful reducing agent, generating great heat in forming alloys. It 
is sometimes added to nickel to remove traces of oxide which may 
be dissolved in the metal, but if any excess of magnesium is used, 
it does not alloy with the nickel. In the same way, phosphor 
bronze — an alloy of copper and tin which has been fluxed with 
phosphorus — generally in the form of copper phosphide or tin 
phosphide, may lose its best properties and be rendered worthless 
by a slight excess of phosphorus. Only when the impurities or 
foreign metals dissolve freely and become incorporated in the 
alloy, can the founder afford to ignore them. In many cases the 
content of foreign elements is so very small that it cannot be 
reckoned as a factor in the final alloy, except by showing either 
better or worse results than the alloys which do not contain them. 

Pertinent points in alloying. — The main points to be con- 
sidered in manipulating metals for the purpose of making alloys 
are the fusibility, volatility, fluidity, and chemical affinity of the 
combining metals in the heat, and the homogeneity of the alloy in 
the solid condition. Some metals only combine in limited pro- 
portions. Lead is said to be capable of holding about 2 per cent 
of zinc ; copper takes up about 8 per cent lead, and zinc is said to 
be saturated with iron at 5 per cent. Since aluminum has been 
added to the brass founders' repertory, the difficulties of alloying 
have been increased. Aluminum plays havoc with any alloy which 
contains lead, it has great affinity for silica, therefore sprues or 
scrap with sand adhering must be thoroughly cleaned. If alu- 
minum gets mixed with soft solders it destroys the adhesive or 
fluxing properties of the alloy. 

Aluminum as a flux. — The indiscriminate use of aluminum in 
alloys has done great injury to the reputation of the metal as a 
mixer, and hindered the usefulness of the bona fide aluminum 
alloys, particularly aluminum bronze and aluminum brass. As a 
deoxidizer, aluminum is a snare and a delusion, for when it comes 
into contact with the oxide of any other metal, and heat is applied, 



Methods of Making Alloys 57 

it displaces the oxygen of the other metal to form oxide of 
aluminum (ALOs) and the last condition of that metal is worse 
than the first. 

Aluminum brass alloys are correctly made in either of two 
ways; first by introducing metallic aluminum into molten brass, 
or second, by introducing zinc into melted aluminum bronze. Re- 
peated remeltings of this, or indeed any of the brass alloys are 
not advisable, unless allowance is made from time to time for 
loss due to the volatilization of zinc. 

In these days of concentrated products and short cuts to 
fortune, it is the easiest thing in the world, (if we can believe the 
story the ad writer tells) to produce alloys in definite proportions 
with metals which are known to be difficult to combine. Special 
alloys are manufactured in a highly condensed form to meet the 
needs of brass founders and to avoid palpable difficulties in the 
way of reducing and combining elements of widely different 
qualities. The introduction of ferro-manganese, ferro-aluminum, 
ferro-zinc, copper-manganese, silicon-copper, aluminized-zinc and 
phosphorized copper and tin, as intermediary alloys, has reduced 
the difficulties in connection with the production of complex 
alloys to a minimum. 

Disparity in melting points of metals. — A common difficulty 
in making alloys is the disparity in the fusibilities of the metals. 
This is generally overcome ' in foundry practice by fusing the 
metal with the highest melting point first and then adding the 
more fusible elements in the solid condition. With brass, bronze 
and nearly all the copper alloys, this practice commends itself as 
giving the most economical and satisfactory results. But with 
volatile metals in conjunction with highly refractory metals, as, 
Zn-f-Fe or Sn+Pt, advantage is taken of the solvent action of a 
metal of low fusibility when melted in contact with one of high 
fusibility. If zinc were introduced into molten iron the loss of 
zinc would be considerable, the ebullition of the iron would be 
dangerous and the composition of the alloy would not bear the 
intended proportions. 

Whereas, when finely divided iron is mixed with molten zinc, 
a definite proportion of the iron is absorbed and the two metals 



58 Practical Alloying 



combine with ease. Again, platinum is so difficult to fuse as to 
require the aid of the electric arc or the oxy-hydrogen blowpipe ; 
but if a more fusible metal is reduced to the molten state and small 
quantities of platinum are gradually added, many useful platinum 
alloys may be produced. Nickel also is difficult to fuse by itself, 
but if it is to be alloyed with aluminum or copper as in the Ger- 
man silver alloys, the best practice is to place the metals in the 
crucible in layers, with powdered charcoal between, and charge in 
the same manner as brass. 

Very often the temperature and the order in which the metals 
are introduced to each other in the crucible are matters of im- 
portance. Alloys containing copper, lead, zinc and tin, are more 
readily made to specification if the metals are melted in that order 
and the metal is raised to the proper heat immediately after the 
last admixture. 

Alloys of metals which melt below a red heat may be made 
by simply fusing the metals together, but combinations of volatile 
and readily oxidizable elements require more careful treatment. 
Alloys which enter into chemical combination, in atomic propor- 
tions, as SnCua may be remelted without undergoing any change 
in the ratio of the constituents. Unfortunately, very few alloys 
of practical utility can be made in atomic proportions. 

Mr. Parsons, the inventor of manganese bronzes for pro- 
pellers, claims that the elements in his alloys are combined in 
atomic proportions. "This renders the alloy much more stable 
than when not so combined, and if a quantity is passed through 
an ordinary reverberatory furnace and exposed to the action of an 
oxidizing flame for a considerable time, no appreciable difference 
is made in the composition of the alloy." This is an ideal alloy, 
according to the description, but the real thing has its drawbacks. 
Like all sluggish metals it gets more sluggish every time it is 
remelted, and the loss of the combined alloy is considerable. Be- 
sides, all metals in the molten condition absorb gases, this one 
included. 

In melting crucible steel, the metal, as soon as it becomes 
liquid, is said to be clear melted. If poured at this stage the 
ingot would be honeycombed with blowholes, due to the gaseous 



Methods of Making Alloys 59 

condition of the metal. By raising the temperature and adding 
small quantities of silicon-spiegel or other substances which are 
either capable of combining with the gases, or of increasing the 
solvent action of the steel, sound ingots may be obtained. In all 
the foregoing examples, it should be observed that crucible melt- 
ing is implied. The fuel should not come in contact with the 
metals in making alloys. 

Melting anti-friction alloys. — Perhaps no class of alloys have 
suffered more from careless melting and wrong methods of com- 
bining the constituents than the white anti-friction alloys. Anti- 
friction alloys are based on the low coefficients of friction and 
high atomic volumes of the components, compatible with certain 
degrees of fusibility, hardness and wearing qualities. Much 
depends on the physical structure and condition of these alloys for 
keeping down friction. They should be close-grained and thor- 
oughly homogeneous. We know that many cheap brands of anti- 
friction metals are made by melting antimonial lead and small 
quantities of tin together, and sometimes these compounds are 
dignified by the name of babbitt metal. Also, it is customary in 
some quarters, to cast steam fittings from mixtures of scrap 
brass, scrap copper, and additions of lead or tin to bring them 
up or down to the standard of the firm making the goods. Scrap 
has its legitimate use in the making up of alloys but it is not 
always economical, nor good for building up a reputation. 

There are other methods of preparing alloys than by fusing 
the metals in a crucible or other furnace, but as they have not 
reached to any extensive application in the arts, we can afford to 
pass them by. Nevertheless, there still remains many undevel- 
oped theories relating to alloys, many phenomena of metals in 
conditions of contact, in solution and in solid combinations, to 
stimulate research and give rise to a better understanding of the 
science of combining the metallic elements. 

Brass foundry melting ratios. — Brass foundry practice relat- 
ing to the methods of melting and mixing the alloys is a theme 
deserving the interest of manufacturers and tradesmen alike; 
nevertheless, statistics and data illustrating the melting ratio of 



60 Practical Alloying 



the various alloys, or the methods of dealing with the combining 
elements in the crucible, furnace, or cupola, are practically non est. 
The melting methods practiced in various foundries are the 
natural outcome of different and divergent experiences. The iron 
founder has devised a system of producing fluid iron in the cupola 
which he considers unapproachable either in economy or in its 
effect on the ultimate product; that is, the castings. The brass 
founder has improvised other means of obtaining the same end, 
while the steel founder has improved on the brass founder's 
method to suit the conditions most desirable for the making of 
steel castings. No sane man would for one minute question the 
purpose of the several methods which have now become tradi- 
tional. They are based on rational ideas and long experience in 
the art of reducing respective metals to the proper fluidity re- 
quired for running into molds and producing perfect castings. 

It is generally acknowledged that the vast amount of inde- 
pendent thought and experimental research which have been 
accumulated in determining the melting ratio of cast iron in the 
cupola, have led to a more economical system of cupola practice, 
as well as to a better understanding of the materials required to 
produce fluid metal in the best condition suited to the castings to 
be made. So much must be granted to the leaders in modern iron 
foundry practice. 

By a long course of practice, coke has been established as the 
ideal fuel for melting cast iron in the cupola, and iron foundries 
have benefited most by the discussion of the merits of fuels, and 
the economics of melting iron, for the foundry. 

In the brass foundry things are different. Melting records, 
if they exist, are retained for private use only. Brass founders 
are the most conservative of foundrymen, they keep tenacious 
hold of so-called trade secrets to their own detriment, they are 
biased in favor of obsolete methods, and in many cases they must 
either be debited with a lack of interest or energy, or else a secret 
satisfaction with the legacy of their predecessors in the business. 
No one has yet dared to particularize any one fuel or mixture of 
fuels as the best for melting brass founders' alloys. It would ap- 
pear that the ratio of fuel required to melt bronze or brass alloys, 



Methods of Making Alloys 61 

or the influence of different fuels on similar metals or alloys, are 
subjects which have escaped the serious notice of the average 
brass foundry worker. 

The writer has frequently had occasion to melt the standard 
bronze (copper 90, tin 10) in crucible furnaces with natural and 
forced draughts, in reverberatory furnaces, and in the cupola, and 
his experience has proved that some fuels are better adapted to 
the respective methods of melting than others. For instance, 
charcoal is the most convenient and economical fuel for crucible 
furnaces having natural draught; coal is the best fuel for the 
reverberatory furnace, although the low cost of crude oil has led 
many manufacturers to consider its application to this class of 
furnaces; and coke is certainly the fuel best suited for melting 
in the cupola, the most expensive and uncertain of all the melting 
methods practised in the brass foundries. 

Quick melting, and the process of collecting molten metal on 
the hearth, are against economy with alloys melting at from 1200 
degrees to 1800 degrees Fahr. ; besides, in the cupola, the fuel is 
in contact with the bronze, and gases and impurities are absorbed 
by the molten metal from the waste products of combustion. 
While it has been proved that the conditions of melting in the 
cupola have direct influence on cast iron, either in removing unde- 
sirable elements, or in building up the metalloids to a required 
standard, this quality is a decided hindrance to the successful 
melting of brass alloys in the cupola. To obtain satisfactory 
results the pressure of the blast must be lowered and the more 
fusible metals, tin, lead, zinc, must be mixed in the ladle instead 
of passing through the cupola to form the alloy. This adds an- 
other objection to the practice of melting bronze in the cupola, 
if the composition, tin, lead, etc., is added to the molten copper 
when it is tapped out. The resulting alloy is not so homogeneous 
as when the metals are melted together, as is done in the rever- 
beratory furnace and in crucibles. 

When we take into account the great variety of alloys in use, 
their peculiarities, and the high cost of metals, crucibles, and fuel, 



62 



Practical Alloying 



to produce them, we can readily understand how it is that no hard 
and fast rules have been established in brass foundries. Add to 
this the diversity in the character of the work, the lack of uni- 
formity of methods in foundries producing the same class of 
work, and the difficulty of securing reliable reports of the amount 
of fuel used in melting metal, or the relative cost of fuel to metal 
melted in brass foundries, is at once apparent. For some time I 
have been taking note of the melting ratio of one alloy (copper 



TABLE IV 

Melting Ratios 















"3 




T3 








to 


.2 .2 










t* 


2 S 


2 "o 




s « 


Method 


Fuel 




fi ° 


to ~0 

a a 




3 8. 








IS S 

"a, °- 


•a s 
— o 




S 






3 

a 


O 
l-J 


a. 


1. . 


400 


Crucibles (Natural Draft) 


Charcoal 


318 


0.89 


1.25 


2. . 


400 


Crucibles (Natural Draft) 


Purified Coke 


300 


1.22 


1.33 


3.. 


400 


Crucibles (Forced Draft) 


Equal to Connellsville Coke 


348 


2.18 


1.12 


4.. 


400 


Crucibles (Natural Draft) 


Coal 


325 


1.04 


1.20 


5. . 


17305 


Cupola 


Equal to Connellsville Coke 


2184 


7.93 


7.91 


6.. 


2240 


Reverberatory furnace 


Coal 


1768 


3.57 


1.26 



9, tin 1), and also the influence of different fuels and methods 
of melting on the same. Table IV is the result of several 
observations and a comparison of many interesting points which 
may be helpful to the brass founder. 

In all experiments ingot copper and tin were used. Where 
crucible melting was the method employed, 200-pound crucibles 
were used and about 3 inches of coke space was allowed all 
around the crucible. The fuel weights given include kindling the 
furnace and melting the metal for castings. Test bars were made 
from each sample, the best results being obtained from No. 2. The 
bars were turned to %-inch diameter. No. 2 gave a tensile test of 
19.4 tons per square inch, with an elongation of 16 per cent in 10 
inches. No. 5 gave 17.6 tons, with 14 per cent elongation ; in this 
instance the tin was melted in the ladle and the copper was tapped 
from the cupola on top of that. In another trial, not given in the 
table, mixed metal was put through the cupola with very inferior 



Methods of Making Alloys 63 



results. The loss in melting was 10.14 per cent in a total of 27 
cwt., and a test bar similar to those mentioned gave only 14.8 tons 
tensile strength and 8 per cent elongation. 

Coal is recognized to be the most congenial fuel for crucibles, 
but coke or charcoal is more convenient and more economical. 
Oil and gas are both preferable to solid fuels for brass melting 
in reverberatory furnaces, if it can be shown that the quality of 
the metal produced is equal to that received by the older methods 
of melting. The heat is easier controlled, the space required for 
storage of fuel is less, a pipe or a tank taking the place of the 
coke or coal heap, and the price of fuel per 100 pounds of metal 
melted is so much cheaper that it behooves brass founders who 
use reverberatory furnaces to inquire into the merits of some of 
the modern oil or gas furnaces of that description. If an engineer 
were confronted with a problem of this kind, he would reduce it 
in a twinkling to a formula. By means of some abstruse equa- 
tion in algebra, he would prove that as so many heat units are 
required to melt a metal, the fuel best suited for the purpose is 
that which produces the required caloric in the quickest time at 
the lowest cost. But foundrymen know the uses of arithmetic 
better than to reverse the order of progress when dealing with 
purely physical phenomena. It is a remarkable fact that, while 
the metals have been discovered or confirmed in their characteris- 
tics by scientists, the bulk of the useful alloys have been due to 
the experiments and researches of scientific nondescripts. Bab- 
bitt, Muntz, Dick, Parsons, and many other inventors of alloys, 
were more deeply interested in the practical results than in the 
scientific effects of their experiments. The work of the Alloys 
Research Committee and similar bodies has not been the means 
of profit that it might, because it failed to consider the influence 
of fuel on metals in ordinary refining or brass foundry processes. 
In contrast to this, it may be here pointed out that the progress 
which has been made in the past decade in electro-metallurgy, 
has developed kindred sciences, notably metallography and crys- 
tallography, to such an extent that we are now beginning to 
understand the defects of the older systems of reducing metals. 
Pure metal is easier obtained by electrolytic methods than by any 



64 Practical Alloying 



other, simply because there is no contamination in the source of 
heat or energy in the process of separation or combination. The 
increased demand and manufacture of pure copper and aluminum 
is largely due to the cheapening of electrical methods for separat- 
ing the metals from their impurities. The changes which have 
taken place in metallurgical methods and refining processes indi- 
cate the trend towards purity in modern times. And now appears 
the point of this digression. Of what avail is pure metal melted 
in contact with impure fuel? Electrolytically refined copper 
should produce superior gun metal castings in the foundry, if 
melted and alloyed under suitable conditions, but if ordinary care 
and inferior fuel are used in the process of reduction, the chances 
are that G. M. B.'s or the common tough copper would give re- 
sults equally as good. Pure copper absorbs impurities more 
readily in the furnace than impure, because the impurities in the 
latter, which are the result of environment in the raw state, or 
chemical affinity in the process of refining, tend to repel the 
further assimilation of extraneous matter. It becomes evident, 
therefore, that any attempt to reduce the melting ratio in brass 
foundries to figures must also deal with the final condition of 
the metal when it has been turned into castings. To sum up, the 
melting ratio in brass foundries is not a question of economy only; 
the nature and requirements of the work to be cast, and the 
effects of the fuel on the metal and the crucibles, or furnaces, 
are important factors in the ultimate cost and utility of brass 
founders' castings, and it is an open question whether the associa- 
tion of gold, silver, bismuth, arsenic and nickel in the ingot cop- 
per of former days was detrimental to such castings. 



VI 

COLOR OF ALLOYS 

ON a color basis, the useful metals are divisible into three 
classes, red, white and yellow. Copper, silver and gold 
may be taken as representative shades in this metallic 
tri-color. Contrary to the popular idea, the colors that 
may be obtained by alloying different metals and metalloids are 
neither numerous nor well defined. The scale of metallic lusters 
is limited, and it is less under control than the gamut of musical 
sounds. Nevertheless, the range of tones, harmonies and colora- 
tura is governed by similar principles. Light vibrations and 
sound vibrations give positive results in color and pitch, and 
artistic effects follow the interchange of relative tints and tones. 
But owing to this limited, three-fold battery of metals at our 
disposal, all our decorative castings come out in shades of copper- 
red, golden-yellow or silver-white. 

These bright colors lend themselves to beautiful contrasts 
with hammered black iron, polished woods, stones and building 
materials generally, so that in architecture, chromatic blends de- 
light the eye, and castings are almost equal in importance to any 
of the other decorative media. John Bunyan was right when he 
fixed upon eye-gate as one of the principal entrances to the human 
citadel. Color is not only a comforting eye food, it is a stimulant ; 
it is as graceful as spice to the nostrils or sauce to the palate; it 
encourages the use of ornate expression and dispels dinginess; it 
gives the human outlook an optimism that would be sadly missed ; 
it turns the dull gray matter of life into a garden and blends in 
kaleidoscopic beauty, form and feeling in line and curve, distance 
and the eternal verities. Monochromes, monotones and mono- 
syllables have their uses in the elementary stages of art treatment. 



66 Practical Alloying 



but color values, chords and word pictures are on a higher plane. 
Thus it happens, where the self color of alloys falls short, the art- 
ist in metal work has recourse to surface coloring, staining, bronz- 
ing, inlaying, enameling, damascening, electro-plating, japanning, 
etching and lacquering for the complemental effects and colors. 

Decorative processes. — These interesting processes are be- 
yond the scope of this work, but a passing reference might be 
made to the numerous subtle and permanent decorative results of 
applying metallic compounds, or of depositing a film of one metal 
upon the surface of another. The lasting effects of fire gilding 
and electro-deposition are not to be compared to the temporary 
exotic decorations which can be put on with a brush and which 
depend upon varnish to fix them. In the one case there is a 
true deposit or alloy of metals, in the other, only a stain or film 
of color. Some time ago Mr. Sherard Cowper-Coles described 
a new process of blending metals which he discovered 
when conducting some experiments on the annealing of iron, 
"that metals in a fine state of division, to a temperature 
several hundred degrees below their melting point, in contact with 
a solid metal, volatilize, or give off the vapor that is in the form 
of a powder, when heated, condenses on the solid metal placed in 
the powdered metal. 

"This discovery has recently been turned to account for the 
inlaying and ornamenting of metallic surfaces, enabling results to 
be obtained similar to damascening, but with the additional advan- 
tage that there is no risk of the metals finally separating, as is 
often the case in damascening. The new process also enables a 
variety of effects to be obtained and a number of metals to be 
blended together which has hitherto been impossible, and alloys 
of many colors and tints to be obtained in the one operation of 
baking. The thickness and depth to which the metals are to be 
inlaid and onlaid can be controlled at the will of the operator. 

"The process consists in coating the article with a stopping- 
off composition, those portions which are to be inlaid being left 
exposed. The composition is about the consistency of cheese, so 
that it can readily be cut with a knife ; the design is traced with a 
sharp edged tool and those portions to be removed are lifted and 
cleared away. The object thus prepared is placed in an iron box 
containing the metal which is to be inlaid in a powdered form. If 
zinc is the metal to be inlaid, zinc dust is the powder that will be 
employed, which is a product obtained direct from the zinc smelt- 



Color of Alloys 67 



ing furnaces. The iron box holding the powdered metal and the 
objects to be ornamented is then placed in a suitable baking oven 
and heated to a temperature many degrees below the melting point 
of zinc, which is 686 degrees Fahr., so that the temperature to 
which the zinc dust is heated is about 500 degrees Fahr."* 

This is really a burning-in process and the metals blended 
are definitely alloyed and unalterable. A soft transition from the 
inlaid metal to the surrounding metal is obtained, also some 
beautiful color effects, the process being applicable to iron, cop- 
per, zinc, cobalt, nickel, antimony and aluminum. 

Dissolving metals out of alloys. — Another method of obtain- 
ing variety in the coloration of metals is to dissolve certain 
metals, as copper, zinc, aluminum, etc., out of alloys containing 
them. This may be done with acids, only sweating out a portion 
of the more fusible metals. Goldsmiths make the changes of 
color in this way in the manufacture of articles of luxury. The 
one great drawback to the fixing of color values in metals is the 
susceptibility of the base metals to atmospheric influences. The 
metals tarnish quickly, especially in exposed conditions, and so 
we apply paints and preservatives to check deterioration. Chem- 
ical bronzes which produce color effects on metals are simply 
stains due to chemical reactions between the acids and the metals. 
Such applications of acidulated washes give various shades with 
alloys which can be fixed by lacquering, japanning or coating with 
some inert transparent substance. For example, the very antique 
looking green bronze of the art dealers' ware is obtained by 
alternate applications of dilute acetic acid and the fumes of am- 
monia on common brass articles. 

Mechanical color effects. — Peculiar mechanical color effects 
are sometimes obtained by electro-plating a bar or ingot of soft 
metal with a film of harder metal and then rolling or pressing the 
bar or ingot into a sheet or other shape of larger area. By this 
spreading action the hard surface deposit is broken into irregular 
forms and a marbleized appearance is produced. Again, metals 
may have colors impregnated by firing articles coated with certain 
pigments in a muffle furnace. Some metals are capable of form- 



*From Journal of the Society of Arts, No. 2793, Vol. LIV, June 1, 1906. 



68 Practical Alloying 



ing volatile compounds at comparatively low temperatures, espe- 
cially in the presence of reducing gases, and these volatile com- 
pounds will penetrate the surface of other metals, giving a 
characteristic stain of a permanent nature. 

Tinning is another method of coloration, although as a rule, 
articles are tinned with quite another object in view. By dipping 
the heated article in a bath of molten alloy — many other metals 
besides tin may be used in this way — exposed parts acquire color 
from the metal in the bath. 

Colors of alloys. — Coming to alloys for castings, some of the 
color changes produced by mixing various metals will now be 
noted. But first let it be understood that such alloys, besides 
beauty of color, must possess certain stable qualities which will 
make them suitable for working up and turning into articles of a 
strong, useful character. The color of alloys is modified in 
greater degree by metals in the following order, according to 
Ledebur: Tin, nickel, aluminum, manganese, iron, copper, zinc, 
lead, antimony, platinum, silver, gold. 

Thus an alloy of one part tin and two parts copper is white, 
but nearly two parts of zinc must be added to one of copper to 
whiten it and more remarkable still, one part of aluminum has a 
positive effect on nine parts of gold, this alloy being a compar- 
atively soft white metal. Common yellow brass is a blend of red 
and white metals, the strongest alloy in this class being copper 
63 parts, and zinc 37 parts, the color being full yellow with a cop- 
per content varying anywhere between 60 and 75 per cent. The 
copper color is not thoroughly saturated until zinc reaches 60 per 
cent, and beyond that quantity the increase of zinc has a decided 
zincy white effect. 

For dipping brass, the best results are produced with alloys 
of copper and zinc only, preferably with zinc ranging from 20 
to 30 per cent. Sometimes tin in small proportions is added, but 
if more than 1 per cent is used, a greenish hue is given to the 
yellow of the brass, and if crystallization of the tin occurs, a nasty 
mottled appearance is given to the work when it is dipped. How- 
ever, where the work is partly polished, tin adds brilliance. A 
good mix of this kind contains copper 72.5, zinc 27, tin 0.5. On 



Color of Alloys 69 



the other hand, lead, while it facilitates machining, darkens the 
color, and when the articles are dipped, cloudy streaks betray the 
trail of the base metal. The effects of other elements foreign to 
the true copper and zinc dipping mixtures are mostly fatal to the 
gilt-like beauty of fine yellow brass fresh from the dip or acid 
bath. By fine yellow brass, an alloy containing not less than 70 
per cent copper is generally understood. Red brass ranges in 
copper from 80 to 90 per cent, with 1 per cent of lead in addition, 
if the work is to be machined. 

Colors of Bronze or Gun Metals. — Bronze or gun metals, the 
chief constituents of which are copper and tin, have rich, deep 
hues that may be graded from red and reddish yellow to grayish 
white, according to the tin content. Tin, from 3 to 9 per cent, 
gives reddish shades, and increasing this element from 10 to 14 
per cent, orange and yellow shades appear; at 18 to 23 per cent 
a creamy white luster describes the polish of finished parts and a 
beautiful oxidized silver appearance is given to the rough castings. 
Very few foundrymen seem to realize the difficulties in controlling 
shades or intensity of color in consecutive heats of the same alloy. 
Owing to the volatile and oxidizable nature of the average com- 
ponents and the varying effects of different temperatures and 
rates of cooling on the alloys, the color of the castings from two 
or more heats of a particular alloy do not always match. These 
mismatches of color are more readily detected in polished work, 
hence we have another reason for the use of tinted lacquers, 
namely, to impart a uniform tint to the color of the work. This 
question of the color of castings is a very important feature in 
some branches of brass founding, and in the arts. 

Architectural and decorative brass founders are continually 
confronted with this color problem. When two castings of the 
same alloy do not match it offends good taste to see them placed 
side by side on a job. Uniformity of color can only be insured by 
adhering to the exact composition of the alloy, by using always 
the same brands of ingot metals, by melting under the same con- 
ditions ; and by casting at the same temperatures. To emphasize 
the importance of the last mentioned condition, let me cite a case. 
A casting which had been partly machined developed a flaw. The 



70 Practical Alloying 



defective part was burned with a spare metal left over after 
making the casting and yet, when it was finished, the burned part 
was distinctly visible, owing to the marked difference in the color 
at that part. In fact, it had what you might call local color, a 
very undesirable quality in a casting, however agreeable it may be 
in novels or art products. The coloring action of some common 
elements used in alloys is worthy of study. Some of the general 
effects are indicated, in so far as they affect the copper series. 

Color action of metals iji alloys. — Lead deepens the color of 
copper alloys. It is largely used to assist the copper in red metals 
and also to give gun metal a more coppery appearance than the 
actual copper content alone would produce. 

Zinc improves the casting qualities of copper alloys, but has 
quite the opposite effect on the color that lead has. 

Aluminum gives a mottled surface due to crystallization of 
that element. One per cent added to yellow brass produces a 
good imitation of pale gold. 

Phosphorus, by closing the grain, allows of a higher polish 
on all alloys. 

Arsenic has a similar effect, but it is now only used for specu- 
lum. 

Bismuth and manganese produce rose-tinted effects and im- 
prove the luster. Bismuth has a powerful effect on all the white 
colored metals, giving a warm tone to German silver alloys con- 
taining zinc, tin or aluminum. 

Antimony has a similar result as regards color, but it is a 
dangerous element in alloys requiring strength. The cohesive 
force of antimony is poor. 

Copper added to white alloys gives increased luster, greater 
ease in tooling and better casting qualities. 

Mercury, about 1 to 1.5 per cent, added to the standard ord- 
nance bronze, (copper 90, tin 10,) produces a beautiful rose- 
pink-tinted metal which makes fine contrasts with other gun 
metal, brass or silveroid castings. Great care must be exercised 
in adding the mercury to the barely molten tin intended for the 
bronze mixture. 



Color of Alloys 71 



Venus metal, an alloy of equal parts of copper and antimony, 
brittle for delicate parts of a design. 

An alloy used for objects of art and which resembles fine 
gold, consists of copper 92 parts, aluminum 6 parts, gold 2 parts. 

Non-oxidizable alloys generally have nickel as a base and 
platinum as an ingredient. Two mixtures of this class follow : 

No. 1 — Nickel 90 parts, tin 9 parts, platinum 1 part. 

No. 2 — Nickel 34 parts, brass 66 parts, platinum 3 parts ; 
platinum black may be used. 

Owing to its high cost, platinum is not much used for alloys 
for casting, but manganese is sometimes used as a substitute. 

Alloy for statuary bronze. — An alloy recommended by 
Brantt for statuary bronzes and objects of art for outdoor posi- 
tions which admits of simple treatment by washing with pyro- 
sulphides, chlorides, etc., and becomes coated with a rich black 
patina capable of being polished, consists of copper 77 parts, tin 
6 parts, lead 17 parts. This alloy also lends itself to some fine 
contrasts with silveroid, the tones of these two metals being easily 
controlled and ranging from the fine gray appearance of matte 
silver to the velvet black enamel of the genuine patina, with in- 
termediate shades of gold and burnished silver in relief. 

Niello-silver, an alloy consisting of copper 1 part, bismuth 1 
part, lead 1 part, and silver 9 parts, and which is filled into the 
incised lines of metal engraving, acquires a bluish color when a 
little sulphur is added. 

A cheap imitation silver alloy consists of zinc 76 per cent, 
copper 17.5 per cent, and nickel 6.5 per cent. The foregoing 
alloys are selected with the object of illustrating some of the nov- 
elties and the limitations of the color scale in metallic productions. 

Japanese pickling solutions. — The Japanese art metal work- 
ers, who understand the coloring of metals better than we do, 
obtain different colors by employing ores or metals with traces of 
gold, cobalt, antimony, tin, silver, etc., for the alloys, and using 
pickling solutions in which they boil the work. Two of these 



72 Practical Alloying 



pickling solutions, given by Prof. Roberts-Austen, contain the 
following ingredients : 

No. 1 No. 2 

Verdigris, grains 438 220 

Sulphate of copper, grains 292 540 

Water, gallons 1 1 

Vinegar, drachms 5 

The various colors and tints are the result of differences in 
the length of immersion and the effects of impurities in the ores 
or of definite additions to the alloys. As soon as the articles 
assume the desired shade or density they are dried, heated and 
lacquered. By making complex alloys containing traces of cobalt, 
antimony, bismuth and other metals, iridescent colors are ob- 
tained. One objection to these surface colorations is that the 
film may be scratched and the self color of the alloy revealed. 

The striking points regarding the color of alloys may be 
summed up as follows: 

First. — That all the known metallic alloys are limited in 
color to shades of red, white and yellow. 

Second. — The alloying of metals for color effects has not 
received the attention it deserves. We know that certain metals 
produce sudden color reactions, as in the examples given, where 
small additions of aluminum in gold, tin in copper, and nickel in 
copper show radical changes. 

Third. — Alloys are mostly blends as regards color of the 
metals, which behave like neutral solutions, the color of the alloy 
being dominated by the color of the metal present in larger pro- 
portion. 

Fourth. — Pigments of every hue may be produced from 
metallic bases, but the metals are in a state of combination with 
the metalloids, in equivalents which destroy completely their 
metallic character and luster. 

Fifth. — The discovery of some system of controlling or im- 
parting color in alloys would be a novel and, unquestionably, a 
useful achievement, but for casting purposes only self colors are 
suitable, and if a new color of alloy is to receive notice, it must 
have a consistent tone and beauty that is more than skin deep. 



VII 

THE NOTATION OF ALLOYS 

THE notation in common use for distinguishing the various 
metallurgic products is, for the most part, a promiscuous 
growth of popular or local characterizations, private 
marks and industrial apothegms. The quality of the 
useful metals, iron, copper, tin, zinc, etc., is generally indicated 
by the brands or grade numbers of the manufacturers. These 
markings may be useful in commercial quarters for fixing a basis 
price in each class, but in the actual founding of metals they are 
of no practical value. Such marks as "best," "best best,'' "treble 
best," "tough" and "G. M. B. } s" (good merchantable brands) are 
supposed to give the buyer a clue to the quality of metals, but in 
reality they only indicate the relative qualities of the produc- 
tions of each individual maker. The "best best" of one maker 
may be no better than the "best" of another ; and the an- 
alyses of "best selected" copper ingots, "virgin" zinc, or "refined" 
tin, varies with the mines and the extraction processes from 
which they are evolved. The marking of metals, then, fixes 
no standard of quality ; the crowns and crosses, the lions and 
the lambs which are impressed on them, are used for the same 
reason as "3 stars" are adopted for certain brandies, — for adver- 
tising purposes. But something more than a trade mark or 
a market brand is needed to guide the purchaser of alloys ; there- 
fore, it is becoming the custom to stipulate the percentage of the 
principal elements contained in modern alloys. For instance, by 
genuine babbitt metal, an alloy containing not less than 80 per cent 
of tin is understood, and in brass foundry parlance, yellozv metal 
signifies a copper and zinc alloy in which the proportion of zinc 



74 Practical Alloying 



does not exceed one-third of the mixture. Vocabularies are made 
up of names, numerals and nuances; but the vocabulary of the 
metal trades is notorious for its numerous inappropriate names, 
meaningless signs and misleading catch-words. The ceremony 
of bestowing a name upon anything is always regarded as being 
of great importance. Babies and ships are christened, churches 
are consecrated, hospitals are dedicated, memorials are erected, 
patents are granted and territories are claimed and proclaimed 
only when the initial ceremony of naming has been accomplished. 
Whatever formalities may take place at these occasions, the gen- 
eral interest is centered in the name which is bestowed. A name 
should, as nearly as possible, focus the purport or the properties 
of the object named. 

There is much to be learned from names, when they are prop- 
erly applied, but a misnomer is always a snare to the tyro and a 
worry to the scientist. "What's in a name ?" is as difficult a ques- 
tion to settle as — "What's without a name?" One cannot give 
utterance to a thought or single out one thing from every other 
thing, until he has invested it with a suitable appellation. The 
metal trade is handicapped by having two sets of terms — the com- 
mercial and the scientific — to distinguish the goods, and in the 
matter of alloys, or mixed metals, the long list of oracular, in- 
formal and arbitrary titles which have been adopted within the 
last half century, has got beyond the capacity of the average metal 
worker. The beauty of chemical nomenclature is, that it always 
supplies accurate information. It is qualitative and quantitive, 
for it tells the nature of a compound and also the proportions of 
its elements ; H2SO4 is a definite substance to the chemist. When 
he sees the familiar formula, he not only thinks of sulphuric acid, 
but, instinctively, he makes a mental note of the order and rela- 
tionship of the constituents. How different is the system by 
which the metallic alloys are formulated. Granted that the alloys 
which form true chemical compounds are comparatively few, 
there is no reason why the components and proportions of even 
the most intricate alloys should not be graphically stated. 

Chemical notation can only be applied to alloys when the met- 
als combine in atomic proportions to form chemical compounds, 



The Notation of Alloys 75 

and it would be difficult for metallurgists to devise a systematic 
nomenclature for alloys with anything like the simplicity and com- 
prehensiveness of the chemical method of designating salts, etc. 
We long, however, for some more rational method of naming 
alloys than the happy-go-lucky system now in vogue. The be- 
wildering array of names, which are allowed to be applied to 
alloys which are the same in substance, is a disgrace to an industry 
based on scientific principles. Metallurgy is probably the most 
comprehensive of applied sciences and the names given to the 
metals belong to all ages and countries. Whatever name has 
been chosen for a metal, the Latin form of it has been generally 
adopted for technical purposes. If metallurgists could devise a 
similar system for naming the metallic alloys, they would bring 
order out of chaos, make it easier to marshal the mixed metals 
into groups, and less difficult to understand what are the essen- 
tial elements in any particular class of alloys. 

Confusion of present notation. — Uniformity is the life of 
science, but there is no uniformity in the metallic hurly-burly. 
Alloys are seldom what they are represented to be. Gun metal 
for ordnance is obsolete, but the name survives. Phosphor bronze, 
which was originally an alloy of copper, tin and phosphorus, has 
been modified and altered beyond recognition as a bronze. Cop- 
per and lead are frequently the principal components of so-called 
phosphor bronzes, the phosphide of tin being conspicuous for its 
scarcity. Platinoid is a high resistance (electrical) alloy, which is 
innocent of platinum. Aluminum bronze as it is now made, is 
not the unique alloy which promised so well some years ago ; a 
pinchback variety has supplanted the genuine alloy, but, to avoid 
confusion, it should be called aluminum brass. It is in reality 
ordinary brass, containing from 1 to 2 per cent aluminum. Ex- 
amples of this sort of thing could be multiplied ad libitum. The 
metals have been named in all sorts of ways. The alchemists 
fancied some metals male, others female. Arsenic is derived from 
the Greek word for male. Some of the metals are named after 
gods, goddesses and stars, as, Titan-'mm, Thor-'mm, Mercury, etc. ; 
others derive their names from the countries in which they were 
first discovered — Cuprum, (Cypress), Germanium, Gallium, but 



76 Practical Alloying 



the origin of names for alloys is too obscure for elucidation. 
Sometimes an alloy is named after its inventor, as Muntz metal ; 
sometimes after the inventor's initial, as Delta, the Greek letter 
beginning the name of Mr. Dick; sometimes the inventor dis- 
guises his identity and the nature of the alloy by a latin suffix, as 
"Partinium;" sometimes by a figurative title, as "Atlas" bronze, 
"Glacier" metal, etc. But the most common names for alloys have 
been illustrative of the uses for which they are suited. Such 
names as, anti- friction metal, steam metal, button metal, type 
metal, fusible metal, convey to the metal worker a general idea of 
the properties of the respective alloys. But none of these metals 
has been standardized and every manufacturer makes them 
according to his own impression of the requirements. Again, 
alloys are usually classified according to their densities, or by their 
most important or predominant constituent, as copper alloys, 
aluminum alloys (light and heavy), tin alloys, etc. In many in- 
stances the names and the classification are at variance. White 
metal, for example, may mean a copper alloy containing zinc and 
nickel, or it may mean a tin or zinc alloy for bearings or patterns. 
Anti-friction alloys are known to the trade by these amongst 
many other titles : babbitt metal, bearing metal, fusible metal, 
patent metal, plastic metal, white metal and anti-attrition metal. 
Again, take German silver alloys: In addition to the standard 
compositions in use in industrial countries for the manufacture of 
tableware and coins, known as German silver and nickel alloys, 
respectively, the brass founder recognizes a host of other products 
in the same class, under a grotesque variety of names, as albata, 
argitan, argusoid, silveroid, silverette, packfong, biddery, etc. 

These examples serve to show how ambiguous the names 
conferred on alloys may be ; how contradictory, how unnecessary ; 
but they by no means exhaust the terms descriptive of anti-fric- 
tion or German silver alloys. The dictionaries and technical and 
classical literature have been ransacked by makers and adver- 
tisers of alloys for names for their wares. Hundreds of catchy, 
high-sounding names have been registered; and there is quite a 
flood of superfluous appellations to be dispelled before anything 



The Notation of Alloys 77 



like a systematic nomenclature, or notation of alloys, can be 
unfolded. 

Systematic notation. — Chemists formulate chemical com- 
pounds by the symbols of the elements present and by their atomic 
relations, the latter being indicated by the numerals attached to 
the symbols. This system is not suited for the majority of the 
alloys, because they rarely combine to form true chemical com- 
pounds, and the complex nature of some allotropic compounds 
would give rise to irregularities. What practical metallurgists 
need is a systematic notation for alloys even if they are mechan- 
ical mixtures, based on the proportions of the components. This 
would embrace all possible compounds of elementary substances 
and include that large and important class of scientifically nonde- 
scrip compounds termed the metallic alloys. There is too much 
mystery about alloys altogether; they are enveloped in scientific 
fog and manufactured in accordance with the tenets of some 
secret societies. I submit that there is as much need for an Alloys 
Act, as there is for a Food and Drugs Act, in our legislative 
administrations, since human lives are sometimes dependent on 
the quality of metals. 

The cue to the construction of a notation for alloys is con- 
tained in the statement already made, namely, that most of the 
useful alloys do not enter into true chemical combination, but 
are simply mixtures of metals which have the power of cohesion 
at ordinary temperatures. 

Atomic formula? can only be used for dual alloys which form 
perfect compounds, as, for example: Ag 3 Cu 2 or SnCu 3 ; but it 
rarely happens that these chemical alloys of two metals are of 
any practical value in the arts. Many of the most useful alloys 
contain three or four elements which are essential to their com- 
position, therefore a system of linking the symbols and the ratios 
of the contents is required to explain these complications. To 
follow the chemical usage and connect figures to the symbols 
would be confusing and altogether an erroneous proceeding. 
Such figures would indicate chemical equivalents where they did 
not exist. To get over the difficulty and for the sake of euphony, 
the first syllable of the technical name of each metal contained in 



78 



Practical Alloying 



the alloy could be taken to form a composite word which would 
give a clear and unmistakable intimation of the components. In 
this way brass would be represented by Cu-Zi, and if the exact 
amount of each element should be known, the parts could be 
indicated by figures thus, CueiZiss. Further, if the brass con- 
tained lead, as in cock metal, the formula would become Cu-Zi- 
Plum, or if it contained tin, as in naval brass, it would be Cu- 
Zi-Stan; with aluminum or any of the earthy metals or metal- 
loids, the first place would be assigned to the least metallic 

TABLE V 

Systematic Notation for Alloys 



Name 



Bell metal 

Gun metal 

Steam metal .... 

Yellow metal . . . 
German silver. . . 

Plumbers' solder 
Bearing bronze. . 

Type metal 

Silicon bronze. . . 



Composition 



Copper 80 parts, tin 20 parts. . . 

Copper 88 parts, tin 10 parts, 
zinc 2 parts 

Copper 86 parts, tin 6 parts, zinc 
6 parts, lead 2 parts 

Copper 70 parts, zinc 30 parts . . 

Copper 50 parts, zinc 25 parts, 
nickel 25 parts 

Lead 2 parts, tin 1 pa^t 

Copper 80 parts, tin 10 parts, lead 
9 parts, phosphorus 1 part 

Lead 80 parts, antimony 20 parts 



Copper 90 parts, tin 8 parts, sili- 
con 2 parts 



Proposed Formula 



Cu-Stan 

(80. 20.) 

, Cu-Stan-Zi 

(88. 10. 2.) 

. Cu-Stan-Zi-Plum 
(86. 6. 6. 2.) 

Cu-Zi 

(70. 30.) 

Cu-Zi-Nick 

(50. 25. 25.) 

Plum-Stan 

(2. 1.) 

Phos-Cu- 

Stan-Plum 
(1. 80. 10. 9.) 

Plum-Stib 

(80. 20.) 

Sil-Cu-Stan 

(2. 90. 8.) 



element, as, Phos-Cu-Stan (phosphor bronze), Al-Cu-Zi 
(aluminum brass), etc. This notation may not be based on 
science, but it would be eminently practical in manufacturing 
circles. It would become a kind of metallurgic shorthand for 
alloys and the metal worker could then understand the composi- 
tion and get a general idea of the properties of the material at a 



The Notation of Alloys 79 

glance. Table V gives some examples of standard formulae for 
comparison. 

There should be a limit to the adulteration of structural 
alloys; there is no limit to the adulterations in the so-called gun 
metals today. Gun metal may consist of any old thing with 
metallic luster and a reddish yellow skin. A proper notation of 
the alloy such as I have outlined here would cure this and 
similar evils and help lift the metal casting trades out of the 
"mixture muddle." 



VIII 



STANDARD ALLOYS 



WHEN standard alloys are mentioned, one naturally 
thinks of the metals which enter into the currency of 
the country, the formulae for the gold, silver, copper 
and nickel coinages. The standards of the mint are 
based on the exchange values of the metals employed, the alloys 
being for the most part compounded of two metals, the less valu- 
able being added in proportions required to cover the cost of man- 
ufacture and the wear and tear of circulation. Consequently, the 
coinage alloys are easily adjusted. Not so the standard alloys 
adapted for the production of castings. The standard metals of 
the mint or the rolling mill are ill-suited for the severer test of 
the melting furnace ; as a rule they are too rich for foundry pur- 
poses. Foundrymen are well aware that it is easier to make more 
perfect castings from some alloys than from others; and the 
nearer an alloy approaches the condition of a simple metal the 
more difficult it is to procure sound castings from it. Imperfec- 
tions due to occluded gases, oxides, crystallization, shrinkage, etc., 
must be reduced to a minimum in alloys which are intended for 
castings more especially when such castings are required for 
structural or mechanical purposes. Thus it is that dual alloys 
have gone out of favor in the foundry and the bulk of the modern 
standard brass founders' alloys are compounded of three or more 
metals. The monetary value of the metals used for such alloys is 
of no technical importance ; what does matter is the purity of the 
metals employed. Electrically deposited metals are, therefore, 
preferable for alloys which have to conform to specification or tp 
attain a given physical standard. Modern investigations have 



Standard Alloys 81 



placed the distinguishing properties of some highly useful alloys 
on an independent platform, and we recognize them as the best in 
their class — standard metals giving advantages in strength, cohe- 
sion and service. Fifty years ago it would have been possible to 
have classified the more important casting alloys into two groups 
— brass and bronze alloys, but now we must add at least three 
distinct series which have taken root in foundry and engineering 
practice. I refer to the high-tension alloys, the anti-friction 
alloys and the light (chiefly aluminum) alloys of modern inven- 
tion. Brass and bronze (copper-zinc and copper-tin alloys) were 
the forerunners of all the casting alloys, but in these days we 
have to distinguish between numerous kinds of high and low 
brass (these expressions refer to the zinc content), white and 
yellow brass, naval brass, malleable brass, aluminum brass and 
many other kinds deriving their names from the introduction of 
metals foreign to ordinary brass. The same thing applies to the 
intricate and widely varying bronzes of the present day. The 
term bronze was formerly employed to indicate an alloy, the 
chief constituents of which were copper and tin, the copper being 
always predominant, but in recent years almost every combina- 
tion of metals possessing strength and toughness may be described 
as bronze. Some notable examples are aluminum bronze, 
which does not contain tin ; white navy bronze with only two per 
cent copper, and some of Fontainemoreau's bronzes having 
neither copper nor tin in their composition. As it would be quite 
impossible to give here in detail the data relating to all the mixed 
metals qualified for classification as standard alloys, we shall con- 
fine our attention to those metals countenanced by engineering 
bodies, narrowing down the list to such alloys as are suitable for 
the production of castings in the foundry. While cast iron and 
cast steel might justly be classed with other standard alloys, it 
would be inconsistent to discuss these products, considering how 
thoroughly they have been examined already. 

Foremost among the useful alloys we place brass, the sim- 
plest and most reliable compound from which castings may be 
made. Brass, in trade circles, is generally understood to mean 
an alloy of two-thirds copper and one-third zinc. But in every- 



82 



Practical Alloying 



day foundry practice, brass may, and does contain other elements 
besides copper and zinc, and the copper content may vary from 
60 to 88 per cent of the mixture, the 60 per cent standard being- 
known as Muntz metal and the 88 per cent standard being what 
is termed red brass. Between these two limits practically all the 
useful casting alloys are to be found. The mechanical qualities 
and physical properties of the brass alloys vary greatly, and, with 
the exception of color, none of the characteristics produced by 
alloying copper and zinc may be deducted from a comparison of 
the properties of the respective metals. Small variations in the 
composition and different methods of manufacture sometimes 
effect great changes. For example, the difference in the tenaci- 
ty of cast brass and cast Delta metal is very marked, as shown 
in Table VI. 

TABLE VI 



Alloy, cast 


Compoiition 


Tensile 

strength, 

tons per 

square inch 


Authority 




Copper 

2 
75 
59 

55.10 
55.00 


Zinc 
1 

25 
40 

43.47 
42.36 


Iron 

1.77 


Lead 

6!io 


Phosphorus 

0.10 
0.83 


12.25 
13.1 
19.0 
23.0 
■ 27.0 


Dr. Anderson 




Mallet 


Sterro metal 


P. Longmuir 
Roberts-Austen 
Baron Rosthorn 



These examples are selected because they represent a fair 
average for each particular alloy. Many higher and lower re- 
sults have been recorded, but in every case the chemical com- 
bination of iron in a brass alloy results in increased tenacity and 
hardness. This is probably due to the difference in molecular 
construction and the greater density of properly made copper- 
zinc-iron alloys. While brass is essentially a mixture of copper 
and zinc, within well defined limits, slight additions of other 
metals are purposely made to facilitate mechanical and manufac- 
turing processes. Table VII embraces most of the mixtures of 
practical importance. 



Standard Alloys 



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Practical Alloying 



Phosphorus is frequently added to brass alloys for the pur- 
pose of increasing the fluidity. The same object can generally 
be obtained by remelting about one-third turnings with two- 
thirds of the alloy, fluxing with sawdust and potash. Aluminum 
and manganese, alloyed with brass, form two series of metals 
now classed with high tension bronze. 

German silver alloys. — German silver may be reckoned as 
nickeliferous brass, copper, zinc and nickel being the essential 
components. The proportions vary, as under, copper 52 to 60 
parts, zinc 28 to 32 parts, nickel 8 to 20 parts. 

In order to determine the best proportions for alloys con- 
taining 8, 10, 12, 16 and 20 per cent respectively of nickel, Hiorns 
made numerous experiments and finally recommended the follow- 
ing: 

I. — Copper 62, zinc 30, nickel 8. 

II. — Copper 60, zinc 30, nickel 10. 

III. — Copper 57, zinc 31, nickel 12. 

IV. — Copper 54, zinc 30, nickel 16. 

V. — Copper 52, zinc 28, nickel 30. 

Very few of the German silver alloys employed for castings 
contain more than 20 per cent of nickel, but the better classes of 
work are generally made by adding one-third nickel to two-thirds 
ordinary brass (2 and 1 alloy) and lead up to two per cent of the 
total mixture. The standard metal for electrical resistance is 
composed of copper 4 parts, zinc 1 part, nickel 2 parts. Another 
alloy of this description called "manganin," contains copper 84 
per cent, manganese 12 per cent, nickel 4 per cent. The presence 
of impurities in these alloys diminishes their value for electrical 
purposes. All the German silver alloys are noted for their bril- 
liant lustre, malleability and hardness. Krupp and other authori- 
ties are agreed that tin is injurious in this alloy, both as to color 
and malleability, but iron, up to 2 per cent, increases the effects 
of these properties. In foundry practice, those alloys containing 
about 30 per cent of zinc and traces of lead and iron, produce the 
soundest castings, but alloys containing iron are not adapted for 
articles of art which are to be exposed to the weather, because 
they acquire a disagreeable color. 



Standard Alloys 



85 



Range of bronze alloys. — As previously stated, the bronze 
alloys are much more comprehensive now than formerly. The 
bronzes proper (copper-tin series) comprise many metals of 
insuperable qualities. The wide range of properties obtainable by 
combining these two metals has no parallel in the metal industries. 
Of all the useful alloys, we could least afford to dispense with 
this series. Standard bronze alloys contain tin in proportions, 
varying from 1 in 4 to 1 in 12. Three well-known grades take 
prominence here, gun bronze, which contains copper 89 to 92 
per cent, tin 8 to 11 per cent; bearing bronze, which contains 
copper 82 to 88 per cent, tin 12 to 18 per cent, and bell metal, 
which contains copper 78 to 86 per cent, tin 14 to 22 per cent. 
The preparation of these alloys is based on the idea of rendering 
copper stronger, harder, more sonorous and easy to cast. And 
just as the addition of lead is advantageous in German silver 
cast work, zinc or phosphorus in small quantities improves some 
of the bronzes. Hence, many modifications and additions to the 
original bronze alloys, giving greater strength, resilience, homo- 
geneity and improved f rictional and anti-corrosive qualities, have 
been adopted in engineering practice. Some examples are given 
in Table VIII. 

TABLE VIII 
Modern Bronze Alloys 





Name 




C 


omposition 






Suitable for 




Gun 


Copper 


Tin 


Zinc 


Lead 


Phos- 






Metal 










phorus 




1. 


« 


88 


10 


2 








Steam metal 


2. 


" 


87 


8 


5 


— 


— 


Propellers, etc. 


3. 


" 


88 


11 


1 


— 


— 


Lighthouse frames 


4. 


" 


86.5 


13 


— 


— 


0.5 


Hydraulic pipes 


5. 


u 


*87.5 


6.25 


6.25 


— 


— 


Bolts 


6. 


" 


85 to 95 


4 to 10 


— 


1 to 5 


— 


Chemical pumps 


7. 


" 


84 to 90 


6 to 10 


4 to 8 


2 to 4 


— 


Steam metal 


8. 


" 


84 


12 


4 


— 


— 


Bearings 


9. 


" 


82 


14 


■ — 


4 


— 


Mill brasses 


10. 


u 


80 


10 


— 


9 to 10 


0.25 to 1 


Locomotive brassei 


11. 


a 


88 to 92 


8 to 12 


— 


— 


0.25 to 0.5 


Deoxidized bronze* 


Nos. 1, 


2 and 3. 


Specified by British Ac 


Imiralty. 








No. 4. 


Specified by French Admiralty. 










No. 5. 


Specified for N. Brit: 


ish Lighthouses. 








No. 6. 


Specified by mining corporations 










No. 7. 


Specified by American manufacturers. 








No. 8. 


Specified by marine i 


engineers. 










No. 9. 


Specified by Colonia 


1 Sugar Co., 


Sydney. 








No. 10. 


Specified by Pennsyl 


vania Railroad Co. 








No. 11. 


C9. Tl. 


, = Tenacity, 19.3 tons 


sq. in. 

























*Tensile strength 14.7 tons per sq 
inches (dry sand casting). 



in.; elongation 23 per cent in 10 



86 Practical Alloying 



Phosphor bronze. — Bronze of any description is such a 
variable quantity in these days that it is difficult to fix a limit to 
the components or the proportions of the components. Phosphor 
bronze in the early stages of its career was simply an ordnance 
bronze with the addition of from 0.25 to 1 per cent phosphorus, 
a decided novelty in the manufacture and character of bronzes 
at the time of its introduction. 

Experience and experiments have wrought many changes 
in the original formula for phosphor bronze — changes not all 
for the better by any means. We have learned that the very 
best use we can make of phosphorus in alloying is to use it as 
a deoxidizer, or as a re-agent which will combine with some of 
the undesirable or weakening elements in certain alloys. And 
the less phosphorus there is in the finished metal, the stronger and 
denser the alloy will be, so that phosphorus is a thing one can 
easily have too much of when making alloys. For foundry pur- 
poses the use of phosphor-tin (5 per cent phosphorus) or phos- 
phor-copper (10 per cent phosphorus) is recommended as the 
most reliable method of getting phosphorus into ordinary brass 
founders' alloys. The most prominent characteristic of phos- 
phorus in alloys is the marvelous amount of fluidity it yields ; its 
most beneficial effect is probably that it lowers the co-efficient of 
friction of most metals. Phosphor bronze was the pioneer of 
the modern bronzes (high tension alloys and anti-friction and 
anti-corrosive metals), which have led to the free development of 
power in machinery and revolutionized the art of engineering 
within the last thirty years. A common error in foundry prac- 
tice with phosphor bronze is pouring the metal at too high a 
temperature. This alloy sets so rapidly that occluded gases, 
always present in overheated metal, have not sufficient time to 
escape and the result is usually a porous, or at least a very much 
weaker casting than would be expected. 

Peculiarities of phosphor bronze. — Phosphor bronze is a 
peculiar metal to work with. It is readily spoiled by overheating, 
prolonged or repeated melting or the presence of certain impuri- 
ties. The best results are undoubtedly had with dry sand molds, 
but with care in manipulating the metal, uniformly good work 



Standard Alloys 87 



can be obtained in green sand, provided the castings are not 
above medium weight. Some 40 years ago the introduction of 
phosphor bronze as a commercial product initiated several new- 
features in engineering. It soon became a formidable rival to 
steel for many purposes. Phosphor bronze was the forerunner 
of the modern non-corrosive, high-tension and anti-friction alloys, 
and even if it has been in some measure, superseded by later 
discoveries, the history of its uses and advantages over ordinary 
bronze would still be full of interest and instruction to the brass 
founder. 

As the introduction of phosphor matches marked a decided 
advance on the flint and steel period of human progress, so did 
phosphor bronze, in its pristine purity, mark an epoch in the 
progress of the mechanical industries. When phosphor bronze 
was first introduced into the foundries, the molders did not un- 
derstand the nature of the alloy and its best qualities were often 
destroyed through improper treatment. In spite of the very 
precise instructions issued with the metal, so many flagrant 
abuses were common in the foundries that the Phosphor Bronze 
Co., of Great Britain, to protect its products, and insure fair con- 
ditions for its products, was compelled to adopt a method of sell- 
ing the metal by contract, in which it stipulated that the contract- 
ing brass founder should bind himself to use it in a particular way 
(dry sand molds were preferred and feeders were considered 
desirable), and to cast it at a particular temperature, the casting 
heat being judged by the color of the molten metal and the 
condition of the break. I can remember having one or two 
secrets in this connection imparted to me when I was an appren- 
tice. I have learned a few more since then, but I am one who 
looks upon all trade practices as open secrets. 

Brass founders are conversant with the old style of making 
phosphor bronze with stick phosphorus, which has been steeped 
in a solution of copper sulphate, dried and enclosed in a tube and 
then gingerly inserted into the crucible containing the molten 
bronze. Very few brass founders are foolish enough to practice 
this primitive and uncertain method now that phosphor-tin and 
phosphor-copper, containing any desired percentage of phos- 
phorus, may be had at reasonable prices. 



88 Practical Alloying 



The metalloids are beginning to play an important part in 
the refining and alloying of brass founders' alloys, but there is 
still much to be done in the way of experiment and research. 
Phosphorus, silicon and arsenic bronzes are simply modifications 
of the ancient metal of the bronze age. We have not had the limits 
of these elements defined, nor a full statement of the properties 
conferred on metallic bodies by these non-metallic substances. It 
is expected that the electric furnace will yet solve many enigmas 
in the reduction of highly refractory or volatile metals, and in 
the manufacture of alloys. The improvements which have been 
made already in reducing aluminum and in refining zinc point in 
that direction. 

The effect of phosphorus on the physical qualities of cast 
iron has always been thoroughly understood, but it is not gener- 
ally known that phosphorus increases corrosion as well as induces 
red-shortness. The properties and peculiarities of phosphorus 
when combined with steel, copper, bronze and babbitt metal are 
not so generally known as they might be. 

Suggestions for melting phosphor bronze. — The following 
suggestions should help to impress on brass founders and others, 
the right use of phosphorus in this connection : 

Phosphor bronze is best melted in a crucible. When it is 
reduced to the molten condition in a brick-lined furnace, the 
phosphorus attacks the silica in the lining, forming a slag which 
increases the waste both of metal and furnace lining. 

Phosphor bronze shows a perfectly smooth surface on the 
ingot, and a characteristic granulation in the fracture. When 
molten it is easily distinguished by its fluidity, mirror-like surface 
and the continuous break of the fluid metal until it sets. 

Phosphor bronze does not assume a pasty condition just 
before setting. It passes suddenly from the fluid to the solid con- 
dition at a certain temperature. Many castings have been cast 
short owing to the metal being cooled too much and allowing it 
to freeze to the sides of the ladle while casting. 

Phosphor bronze castings should not be dipped while still 
hot to blow the cores out. The phosphorus in the alloy renders 
it red-short. 



Standard Alloys 89 



If you wish to see honeycombs all over the castings when 
they are machined, pour your phosphor bronze hot, into unslicked 
green sand molds. Many molders do this sort of thing and 
blame the bronze. The casting cleaner knows whom to blame. 

The best phosphor bronze does not necessarily contain the 
largest percentage of phosphorus. Phosphorus beyond the quan- 
tity required to produce homogeneous metal weakers the cast- 
ings. 

Phosphorus is a powerful deoxidizer, but an excess may 
create a worse evil than oxide. The recognized limit for cast 
iron is 1 per cent, for bronze 3 per cent; the less phosphorus 
there is in the finished metal the greater the resiliency of the 
bronze. 

In steel of 1/30 of one per cent phosphorus would render the 
metal valueless for edged tools. 

Phosphorus introduced into ordinary bronze increases liqua- 
tion and the tendency to segregation. 

Phosphorus makes copper hard and more liable to corrosion, 
but added to bronze — copper and tin alloy — less liable to corro- 
sion. 

Phosphorus in bronze increases the grip of the patina or 
surface oxidation, so much sought after in ornamental bronzes. 

Phosphorus, in conjunction with zinc in a gun metal alloy, 
increases the co-efficient of friction; in conjunction with lead it 
reduces friction considerably. Kunzel was the first to deprecate 
the use of zinc in phosphor bronze. He patented an alloy which 
is now recognized as a splendid anti-friction metal for locomo- 
tive and other bearings liable to heat. 

Phosphorus has great affinity for iron and acts to chemically 
combine brass and iron. This fact is largely taken advantage 
of by brass refiners to neutralize the bad effect of iron upon 
brass. For example, in refining borings, ashes or washings, 
which always contain iron, phosphorus is the agent which is 
commonly used to get the two metals, brass and iron, to amal- 
gamate. 

Phosphorus increases fluidity and fusibility and renders 



90 Practical Alloying 



molten metal very limpid. On this account it is often introduced 
where delicate ornamental castings are required. Sometimes 
even in fine yellow brass work. 

Phosphorus prevents blistering in babbitt metals and im- 
proves the anti-friction qualities of the metal. 

If you tap a heat of gun metal before it is up to the proper 
heat, 0.5 per cent phosphorus will help to make it fluid, but it will 
not do what time and fuel would have done. It is a great mis- 
take for brass founders to rely upon phosphorus as a cure-all for 
dull metal simply because it helps to run the casting. 

Castings in phosphor bronze never suffer from cold-shut. 
Work your sand accordingly and you will be right. 

When you wish to introduce phosphorus into the metal, 
don't wrap a piece in paper and make an exhibition of your agili- 
ty in evading fireworks. A piece of phosphor-copper will do 
the work much better. 

Gun metal — Nowadays gun metal is a term of great lati- 
tude, and it is quite possible to make gun metal, which will 
satisfy the most urgent demands of engineering, with an admix- 
ture of zinc and lead. The British Admiralty do not counte- 
nance the use of lead in gun metal alloys, but America is not so 
conservative, and it has been the common practice there to 
introduce a small proportion of the base metal into gun metal 
alloys intended for high steam pressures. The wisdom of this 
procedure was questioned for a long time, but experience has 
amply proved the fact that it is quite possible to produce with 
copper, tin, zinc and lead, a close-grained metal, which will cast 
well, machine easily, and withstand the highest pressures re- 
quired in modern steam boiler mountings. Steam metal is the 
characteristic name given to this alloy ; the average mixtures con- 
tain copper from 85 to 90 per cent, tin 4 to 8 per cent, zinc 4 
to 6 per cent, and lead 1 to 3 per cent, a typical alloy being, 
copper 87, tin 6, zinc 5, lead 2. 

Anti-acid metal. — Another metal in which lead plays a most 
important part is known as anti-acid metal. It is well known 
that nearly all acids, and for that matter, alkalies, too, dissolve 
or corrode metals and alloys at ordinary temperatures, and with 
an increase of temperature this corrosive action is generally accel- 



Standard Alloys 91 



erated. By many of the newer metallurgical methods the prod- 
ucts are obtained by the wet process, from solutions of the 
ores in the presence of acids. The gain in by-products is consid- 
erable, and the time and outlay required to reduce a given quan- 
tity of metal is generally less than by the old roasting methods. 

This was brought under my notice in conducting a series of 
experiments for an Australian copper mining plant. The water 
ends of pumps and machines through which the concentrated 
solutions of copper sulphate had to pass were made in the first 
instance, from a special anti-acid metal composed of copper 63 
per cent, lead 30 per cent, antimony 7 per cent. This proved a 
very satisfactory alloy for the purpose, but some of the parts 
which were subject to friction or stresses, such as the plunger, 
or the ram, gave out in a short time, and to improve the wearing 
qualities of these parts, a new alloy was made, containing copper 
70 per cent, lead 20 per cent, antimony 7 per cent, tin 3 per cent. 
Even this mixture did not give complete satisfaction, the condi- 
tions were severe and exacting — vibration, continuous working, 
and heavy load — and after one other trial with a modification of 
the last alloy, the engineers fell back upon a gun metal containing 
lead, which has proved useful in bearings and frictional parts of 
machinery. This mixture consists of copper 85 parts, tin 10 
parts, lead 5 parts. Absolutely the best alloy for anti-acid cast- 
ings is antimonial lead, containing lead, 85 parts, and antimony. 
15 parts. Printers' type metal is in this class, but for machinery, 
slow motion and light loads are essential conditions if this metal 
is used. 

Iridio-platinum. — There are no products of human skill on 
which a greater degree of care is expended than the standards 
of weight and measure in use among the civilized nations of the 
globe. Two things in particular have to be considered : accuracy 
and durability. Nature does not furnish any single metal, or 
mineral, which exactly answers the requirements for a standard 
of measure or weight that shall be, as nearly as possible, unalter- 
able. 

The best substance yet produced for this purpose is an alloy 
of 90 per cent of platinum with 10 per cent of iridium. This 
is called iridio-platinum, and is the substance of which the met- 



92 Practical Alloying 



ric standards prepared by the International Committee on 
Weights and Measures is composed. It is hard, is less affected 
by heat than any pure metal, is practically non-oxidizable, and can 
be finely engraved. In fact, the lines on the standard meters are 
hardly visible to the naked eye, yet they are smooth, sharp and 
accurate. 

Aluminum. — In some ways aluminum is a wonderful metal, 
but foundrymen are chary of using it freely in alloys because of 
the troubles which frequently follow, such as segregation, por- 
ousness, cracks, excessive shrinkage, and the difficulty of making 
satisfactory combinations with some of the other metals in every- 
day use for castings. There is a limit to the amount which some 
metals will take up in alloying. 

According to Dr. Richards, aluminum can hold a little over 
1 per cent of lead in solution, and from personal experience with 
aluminum bronze (copper and aluminum mixtures), I have been 
forced to the conclusion that a very small percentage of lead 
exerts a very injurious influence on the physical properties of 
this alloy. 

Aluminum for alloys. — Similarly, if aluminum is to be in- 
troduced for any special purpose into ordinary gun metal, yellow 
brass or German silver alloys, great care must be taken to use 
metals entirely free from lead, otherwise unreliable castings will 
result. The castings as taken from the mold may appear to be 
sound, but when the skin is broken on the lathe, a patchy appear- 
ance, due to the segregation of the lead and the formation of 
oxides in the molten metal, shows up the weakness and irregu- 
larities of a bad mixture. On this account, all metals containing 
aluminum should be kept scrupulously apart from the ordinary 
alloys used in the brass foundry. 

The fact is, with all our modern improvements and cheap- 
ening processes for the increased production of aluminum, we 
are not yet familiar with the use of the metal as a mixer, and 
foundrymen are still seeking for information as to the proper 
use of it in alloys. 

Zinc and aluminum. — Zinc has been found to be the most 
natural alloying metal for aluminum. Indeed, the two metals 
may be combined in any proportions almost as freely as the 



Standard Alloys 93 



brass (copper-zinc), alloys, and with casting qualities equally as 
good. As a general rule, however, alloys of aluminum with an- 
other metal, binary alloys, are seldom satisfactory for castings, 
and many mixtures which are serviceable for rolling, hammer- 
ing, or otherwise working into shape, are utterly useless for 
foundry purposes. Silver and aluminum, copper and aluminum, 
and zinc and aluminum are decidedly the best of the binary alloys 
for castings. 

Nickel-aluminum* alloys. — Nickel aluminum alloys have 
poor mechanical properties and they are difficult to make. Tin- 
aluminum alloys are unstable and weak and magnesium-alum- 
inum, the lightest of all the aluminum alloys, casts badly and 
is subject to great waste and change on remelting. Where cost 
is not a factor and fine grain, color, polish and resistance to cor- 
rosion are important, the silver-aluminum alloys are by far the 
best for ornamental castings, statuettes, etc., from 3 to 5 per cent 
silver being the average proportions. Sometimes 1 per cent of 
copper is added to reduce the cost, or to insure better wear as in 
the case of cast dental plates and fine instruments. The atomic 
weight of silver is exactly four times that of aluminum and their 
specific gravities are in the same ratio. It is believed that this 
has some connection with the characteristic improvement in color, 
grain and resistance to corrosion, which silver-aluminum alloys 
show. 

Imitation silver. — Many imitation silvers and so-called Ar- 
ger.tan alloys are now produced with aluminum as the base. 
The aluminum content ranges from 88 to 94 per cent and the 
alloying metals, copper, tin and nickel, are present in equal pro- 
portions, varying from 2 to 4 per cent. Cowles' ''silver bronze" 
is also a substitute for German silver, but its electrical resistance 
is about forty times greater. Although there is no nickel in the 
composition, it is more closely allied to the standard German 
silver alloys than those having aluminum as the base. The mix- 
ture consists of manganese, 18 parts; aluminum, 1% parts; sili- 
con, Y^ part; zinc, 13 parts, and copper, 67 J / 2 parts. 

Aluminum bronze. — The very first aluminum alloy to come 
into prominence was the now famous, but seldom used, aluminum 

♦Nickelumen is the name now given to alloys of those two metals. 



94 Practical Alloying 



bronze, containing copper 90 to 95 per cent, and aluminum, 5 to 
10 per cent. This is an ordinary heavy bronze, with the tin re- 
placed by aluminum. It is a superior alloy to tin bronze, having 
all the advantages in double the tensile strength, greater resili- 
ence, more artistic appearance and color, no segregation or hard 
spots, better resistance to corroding influences, and, owing to the 
cheapening of aluminum, the cost by weight is now slightly less. 
This alloy has never had a chance to distinguish itself in engi- 
neering practice. Brass founders have not treated it fairly. They 
still persist in varying the formula, and add zinc, tin, lead or 
some other ingredient to cheapen the product with the result 
that aluminum bronze has fallen into disrepute, and aluminum 
brass has been substituted for the bronze for many purposes. 
To those looking for a first-class bronze, giving strong homo- 
geneous castings, no better mixture can be recommended than 
the following : Copper, 90 parts ; aluminum, 8 parts, and phos- 
phor copper, 2 parts. 

Some modifications of this bronze are made by adding tin 
to the mixture, from 2 to 8 per cent, according to the degree of 
hardness required. A good mixture for bearings is composed of 
copper, 95 parts; aluminum, 5 parts, and tin, 8 parts. For a 
close-grained bronze suitable for machine parts and steam metals, 
use copper, 90 parts ; phosphor copper, 2 parts ; tin, 4 parts, and 
aluminum, 4 parts. 

Gun metal alloys. — An improved series of gun metal alloys 
containing aluminum consists of copper, 84 to 88 per cent; tin, 
6 to 10 per cent, and aluminum, 2 to 6 per cent. The hardest of 
these mixtures is suitable for bells and equal to cast steel in 
strength. It must always be borne in mind, however, that metal 
made simply by mixing aluminum and copper does not acquire 
its best properties till it has been remelted several times. For 
all of these aluminum bronze alloys it will be best to make a 
"hardening" of the copper and aluminum, say 50 parts of each. 

Melt the copper first, and add the aluminum gradually, tak- 
ing care to keep the metal in a barely molten state. This alloy 
is very brittle. It is an easy matter, therefore, to add any de- 
sired quantity of aluminum to the bronze. As molten aluminum 
alloys oxidize more rapidly than most of the regular casting 



Standard Alloys 95 



metals, it is well to cover the metal with carbon, and a plumbago 
crucible lid kept on while the metal is melting helps to prevent 
drossing due to the access of air. No flux is necessary. Alumi- 
num is an earthy metal, and anything that would flux it would 
act also on the crucible, to the detriment of the metal. Over- 
heating must be avoided, and when once the metal is ready it 
must not be held in the fire. 

With these precautions, and ordinary care not to mix metals 
of a different class with the aluminum bronzes, sound castings 
are as easily obtained as with ordinary bronze alloys. A spe- 
cially tough bronze has the following composition: Copper, 87 
parts; tin, 10 parts; nickel, 1^2 parts; and aluminum, 1)4 parts. 

Aluminum brass alloys. — Passing to the aluminum brass 
alloys, we get a big range of metals with splendid casting quali- 
ties and wonderful strength and toughness. Ordinary yellow 
brass — copper, 70; zinc, 30 (no lead) — with 2 per cent aluminum 
added, is transformed to a high tension bronze. This metal may 
be used for almost every conceivable casting, from the lightest 
ornament to a ship's propeller wheel. Valves, bearings and fric- 
tional parts of machines are excepted. 

Aluminum brass is the easiest of the ternary alloys to manip- 
ulate. The three metals combine well in proportions ranging 
as follows : Copper, 56 to 80 parts ; zinc, 20 to 42 parts ; alumi- 
num, one to six parts. The tenacity of the alloys varies between 
40,000 pounds and 90,000 pounds per square inch. 

Other metals are sometimes added with good effect, notably 
manganese, between 1 and 2 per cent ; iron and phosphorus, about 
1 per cent ; tin, 1 to 3 per cent. 

To the brass founder accustomed to the pouring of "high" 
brass, aluminum brass presents no difficulty, and this may be one 
of the reasons for its popularity. Due to the comparatively low 
specific gravity of aluminum, ordinary heavy metals in combina- 
tion with it are liable to segregate when cooling down to a solid 
condition and further, the high specific heat, contraction and 
atomic volume, characteristic of the metal, make it difficult to 
get serviceable combinations. These are the main drawbacks 
to the working of the binary alloys, like the copper-aluminum 
bronzes already dealt with, but with the ternary alloys, such 



96 Practical Alloying 



drawbacks, to a large extent, vanish. Nevertheless, each class 
has its own points of excellence, and whether it be the bronze 
or the brass that is used, the artistic as well as the useful and 
economic value of the alloys should be considered. 

Light alloys. — The light alloys of aluminum are more nu- 
merous and generally speaking, more applicable to the modern 
craze for light fittings for automobiles, motor boats, scientific 
apparatus and art metal castings. Classed with the light alloys 
are several combinations of rare metals, or metals requiring ex- 
tremely high tempertures for their reduction, as chromium, 
tungsten, titanium, etc. These are scarcely worth the increased 
cost and trouble, and certainly they are not necessary for ordi- 
nary castings. Used with copper and nickel, manganese makes 
the hardest light alloy of aluminum yet produced. 

Susini alloys. — Susini's alloys contain from 3 to 10 per cent 
of alloying metals, the latter being zinc, copper and manganese. 
He makes the alloy of the three latter separately, melts the re- 
quired quantity of aluminum and then pours the liquid alloy 
into it. 

The three alloys he recommends must contain in percent- 
ages: 



anganese 


Copper 


Zinc 


lto3 


1.5 


0.5 


lto5 


2.5 


1.0 


2 to 8 


4.5 


1.5 



Good casting alloys for small figures and art designs may 
be had with tin and nickel combinations, as for example, tin, 7 
parts ; nickel, 3 parts, and aluminum, 90 parts. This alloy is 
whiter than aluminum and can be more easily soldered and 
polished and gives very sharp outline and detail in sand castings. 

Nickel alloys. — A stronger series are the ternary alloys of 
nickel, copper and aluminum, nickelumen alloys, as they are 
sometimes called, have a great tenacity and a high elastic limit. 
A typical alloy in this class for rolling contains copper, 3^2 per 
cent, and nickel \Yz per cent. For casting purposes the alloying 
metals may be increased up to 10 per cent with advantage, and 
for rigid alloys the nickel content may even, be increased beyond 
the copper. 

An excellent substitute for these nickelumen alloys is com- 



Standard Alloys 97 



posed of aluminum, 91 parts; antimony, 1 part, and phosphor 
copper, 8 parts. An alloy whose specific gravity is nearly the 
same as pure aluminum, is composed of aluminum, 96 per cent; 
antimony, 2 per cent, and phosphorus, 2 per cent. These alloys 
are not so expensive to make as the nickelumen or magnalium 
alloys and they answer quite as well for many kinds of castings. 

Magnalium alloys. — All magnalium alloys (aluminum and 
1 to 10 per cent magnesium), are improved by the addition of 
zinc, 1 to 20 per cent, and there is better wear in the metal, which 
is more homogeneous. For rolling, nickel and copper take the 
place of zinc in some magnalium mixtures. One of these mix- 
tures shows aluminum, 96 parts ; magnesium, 2 parts ; nickel, 1 
part, and copper, 1 part. 

Cheapest aluminum alloys. — After all, the cheapest and 
most reliable of all the aluminum alloys for castings are zinc- 
aluminum mixtures, with possibly small • additions of copper, 
phosphorus or tin. These alloys are well adapted for pattern 
metals. They may be melted and cast by the ordinary foundry 
methods, without the slightest trouble. The average composi- 
tion shows aluminum, 80 to 90 parts ; copper, 1 to 6 parts ; zinc, 
5 to 20 parts ; phosphorus, 1 to 2 parts, and tin, 1 to 5 parts. A 
typical alloy in this class is aluminum, 88 parts ; zinc, 10 parts, 
and phosphor copper, 2 parts. If tin is desired in the mixture, 
phosphor tin may take the place of all or part of the phosphor 
copper. 

These alloys cast smoother and with less oxidation than most 
other aluminum combinations, and the zinc cheapens the product 
without destroying the desirable qualities. 

Aluminum bell metal. — A special aluminum bell metal alloy, 
which may also be used for electrical instruments and ornamen- 
tal wares, consists of the following: Aluminum, 70 to 90 per 
cent; manganese, 5 to 18 per cent; cadmium, 2 to 12 per cent. 
This alloy casts well and takes a brilliant polish. 

Was it aluminum? — An incident in Roman history, well 
authenticated, would seem to indicate that aluminum, instead of 
being new, may be only a re-discovery of an old process. 

It is related by Pliny that during the reign of the Emperor 
Tiberius, a certain worker in metals appeared at the palace, and 



98 Practical Alloying 



showed a beautiful cup made of a brilliant white metal that 
shone like silver. In presenting it to the Emperor, the artificer 
purposely dropped it. The goblet was so bruised by the fall 
that it seemed hopelessly injured, but the workman took his ham- 
mer, and in the presence of the court speedily repaired the 
damage. It was evident that the metal was not silver, although 
almost as brilliant. It was more durable and much lighter. 

The Emperor, so runs the story, questioned the man, and 
learned that he had extracted the metal from an argillaceous 
earth — probably the clay known to modern chemists as alumina. 
Tiberius then asked if anyone besides the worker knew of the 
process, and received the proud reply that the secret was known 
only to the speaker and to Jupiter. 

The answer was fatal. The Emperor had reflected that if 
it was possible to obtain such a metal from so common a sub- 
stance as clay, the value of gold and silver would be reduced, 
and he determined to avert such a catastrophe. He caused the 
workshops of the discoverer to be destroyed, and the luckless 
artificer himself to be decapitated, so that his secret might perish 
with him. It is possible that the cruelty of Tiberius deprived the 
world for centuries of the use of the valuable metal — aluminum. 

Aluminum bronzes. — Aluminum forms some very valuable 
alloys with copper, which may take the place of ordinary bronze, 
phosphor bronze, or steel in certain circumstances. The amount of 
aluminum in the bronzes varies from 2y 2 to 10 per cent. The 10 
per cent bronze is said to be a true alloy ; it does not liquate, and 
the components remain in the same ratio, however often it may 
be recast. It is worth noting that the combination of aluminum 
with metals of higher melting temperatures — copper, iron, nickel 
— produces exothermic reaction, heat being evolved. The metals 
thus alloyed are more homogeneous, stronger, less liable to oxi- 
dization, more fluid and easy to cast. The 7y 2 per cent bronze 
is a good metal for general foundry work, and specially suitable 
for ship fittings, gears and gongs. Aluminum and its alloys 
should be carefully separated from the ordinary brass founders' 
alloys, as the smallest portion in alloys containing lead and in 
certain combinations of tin and antimony produces segregation 
and increases the affinity of such alloys for oxygen to such an 



Standard Alloys 99 



extent as to make it difficult to obtain sound castings. Many of 
the difficulties of handling aluminum in the brass foundry would 
disappear if attention were given to this feature, and the melting 
practice. All aluminum alloys should be remelted; they should 
be melted speedily and cast at the lowest temperature compatible 
with sharp, uniform castings. Experience has taught those ac- 
customed to handling aluminum bronze alloys the importance of 
using only the best grades of copper and aluminum, and also 
the necessity of avoiding, as far as possible, the disturbing influ- 
ences of a third element. 

Light aluminum alloys. — Most of the so-called aluminum 
castings being put into motors and electrical machine parts are 
made from alloys containing copper 4 to 10 per cent, or zinc 8 
to 30 per cent. Zinc forms a cheap and efficient hardener and 











TABLE 


IX 








Aluminum 


Alloys 


for Castings 




Aluminurr. 


i Nickel 


Tin 


Copper 


Antimony 


Tungsten 


Remarks 


per cent 


per cent 


per cent 


per cent 


per cent 


per cent 




98.04 




0.105 


0.375 


1.442 


0.038 


"Wolframinium" 
Analysis by Minet 


96 




0.16 


0.64 


2.4 


0.8 


"Partinium" 


97 


1.75 


0.19 


0.25 


0.25 
Zinc 


0.17 

Magnesium 


by Dr. Richards 
"Romanium" 


100 








lto20 


lto 10 

Phosphorus 


"Magnalium" 
Murman's patent 


96 to 98 








lto 2 


lto 4 


Ruebel's patent 
*"Meteorite" 


07 


0.5 




lto2 


0.5 




Tenacity 11 tons, sq. in. 


98 


1 




1 






Extension 5 per cent 


96 


3 




1 






Tough 


94 


2 




4 






Easily tooled 


i-7 


3 


10 








Malleable 


84.21 




10.23 


5.51 


Silver 


0.09 


Hard, strong 
Mock silver castings 


95 to 98 








2 to 5 
Zinc 




Aluminum silver 


80 






5 


15 




Rigid alloy 



in quantities up to 15 per cent it combines to increase the rigidity 
and strength of aluminum. Tin, as an alloy with aluminum, 
seems to develop brittleness. Sheets composed of equal parts of 
the two metals roll easily when the alloy is newly made, but be- 
come as brittle as glass in a few days' time. Antimony up to 
three per cent combines with aluminum to form some useful 
alloys. The addition of nickel to aluminum produces unstable 
alloys — an alloy containing 4 per cent nickel crumbling to powder 

*Non-corrosive, acid-proof and easily soldered or plated, specific 
gravity, 2.6 to 2.8. 



100 Practical Alloying 



in a few hours after it is cast. Here the introduction of a third 
element is advantageous, tin and copper being suitable for cast- 
ing alloys. Some examples used for castings are givenin Table IX. 

Aluminum brass. — Aluminum brass is perhaps the most 
popular of all the aluminum alloys. It is easy to manipulate pro- 
vided lead and antimony are absent, and castings of great 
strength and brilliancy may be obtained by simply adding zinc to 
aluminum bronze, or aluminum to ordinary brass. The average 
alloys contain copper, 55 to 67 per cent; zinc, 28 to 48 per cent; 
aluminum, 1 to 3 per cent. An analysis of a propeller blade, 
made by a leading company, gave the following result: Copper 
66.95 per cent; zinc, 29.60 per cent; aluminum, 1.93 per cent; 
iron, 0.97 per cent, and lead, 0.48 per cent. The tenacity of this 
specimen was equal to 60,000 pounds per square inch, and the 
elongation about 16 per cent in 10 inches. 

Manganese bronze propellers. — Manganese bronze is recog- 
nized to be the metal par excellence for ship propellers. Its chief 
characteristics are, great transverse strength, toughness, hard- 
ness and fine casting qualities. P. M. Parsons, the inventor of 

ANALYSES OF PARSONS MANGANESE BRONZES 

Sheet metal Ingots for sand casting 

Per Cent Per Cent 

Copper 60.27 Copper 56.11 

Zinc 37.52 Zinc 41 . 34 

Iron 1.41 Iron 1.30 

Tin 0.75 Tin.._ 0.75 

Manganese 0.10 Aluminum 0.47 

Lead 0.01 Manganese 0.01 

Lead 0.02 

this alloy, introduced a cupro-ferro-manganese into the ordinary 
brass and bronze alloys and obtained a wonderful increase in the 
desirable physical properties of the metals, in the case of bronze 
the tenacity showing an increase of 60 per cent. An alloy, the 
approximate composition of which is copper, 58 per cent ; zinc, 40 
per cent; manganese, 1 per cent; aluminum, 1 per cent, gives, in 
cast ingots, a tensile strength of 72,000 to 76,000 pounds per 
square inch, with 20 to 22 per cent elongation. It is stated that a 
properly designed screw propeller in this metal will come much 
lighter and give as much as half a knot increase of speed, as 
compared with an iron or steel propeller, this being due to re- 



Standard Alloys 101 



duced scantlings, smoother surface, etc., and the evils of cor- 
rosion are entirely overcome. Without a doubt manganese bronze 
is second to none for propeller work. Manganese is a reliable 
deoxidizer to use in foundry brass and gun metal alloys ; in some 
ways it is preferable to phosphorus. The latter induces cold 
shortness, and the slightest excess is harmful. Manganese, how- 
ever, may be used freely, from 1 to 6 per cent of cupro-man- 
ganese showing increased tensile strength and elongation. 

Anti-Friction metals. — The so-called anti-friction alloys, 
originally introduced by Isaac Babbitt, have grown to be quite a 
formidable class, indispensable to the engineer in these days of 
high speeds and heavy loads. These white anti-friction metals 
are used almost exclusively for bearings, and they have replaced 
many of the hard bronze bearing alloys formerly used in ma- 
chinery running at high speed or under great pressure. The in- 
troduction of new metals and alloys has wrought extensive 



TABLE X 

Commercial Babbitt Metals 



Tin 


Antimony 


Lead 


Copper 


Zinc 




per cent 


per cent 


per cent 


per cent 


per cent 




78.56 


11.8 


6 


3.8 






34.74 


17.1 


44.25 


3.92 




Arsenic, trace 


64.7 




1 


1.8 


33.35 




- 








Bismuth 




83.26 


9.74 


0.86 


5.50 

Iron 


0.32 


Iron, trace 


1.25 


20.12 


78.28 


0.7 


0.28 





changes and many wonderful improvements in engineering prac- 
tice. The high tension bronzes already mentioned have raised 
the capacity and reduced the factors of safety in materials of 
construction. The modern demand for metals, which shall be 
light in weight, pretty in appearance, not too expensive and easily 
worked into shape, has been met by manufacturers and inventors 
in the later combinations of aluminum, but of all the modern 
alloys, babbitt metal, under whatever name it may appear, has 
proved to be the most useful and economical for machine parts 
in motion. Genuine babbitt metal is composed of tin, 86 per 
cent; antimony, 12 per cent, and copper, 4 per cent, but numerous 
alloys laying claim to superior qualities, producing less friction, 
requiring less lubrication and possessing greater durability, are 



102 Practical Alloying 



now on the market. Analyses of five different brands are given 
in Table X. 

The British admiralty uses alloys in this class ranging in 
tin from 83 to 85 per cent, antimony 7^2 to 12 per cent, copper 
5 to 9 per cent. The utility of lead in alloys for bearings is now 
generally recognized, and these analyses go to show that the 
manufacturers of anti- friction metals are not slow to take this 
advantage. Standard alloys, or alloys subject to tests, may only 
be expected to give satisfaction when the best materials have 
been fairly treated. This is probably the most important fea- 
ture in the manufacture of anti-friction alloys. To summarize 
briefly the merits of the metals used in making these alloys, lead 
is the ideal metal for reducing friction, antimony is the ideal 
hardener, zinc is the best wearing material and tin is the best 
medium for combining all of these qualities. 

The history of the so-called anti-friction alloys reflects 
the history of modern engineering, in miniature. In the 
days when the world and all its works went to the tune 
of "slow and sure," hot journals and squeaking axles were the 
signals for a halt ; in the present day such untoward happenings 
are inexcusable. The market is glutted with anti-friction goods 
— metals, greases, oils, etc., and the plurality of "best anti-fric- 
tion compounds" in these lines is, to say the least, embarrassing. 
It has always been an axiom in engineering that rubbing sur- 
faces should be composed of dissimilar materials, in order to 
economize power and reduce the wear due to friction. Under 
the heading of anti-friction alloys we must embrace two great 
classes of metals, bearing bronzes and the white anti-friction 
alloys. The latter series is by far the most important to the 
general engineer, but we will deal first, and somewhat briefly, 
with the hard bearing bronzes favored by millwright and locomo- 
tive makers from the early days of machine construction. "Brass- 
es," that is, bronze bearings, differ but little in composition from 
ordinary bronzes, but they are supposed to offer little frictional 
resistance when in contact with other metals. The best alloys in 
this group are characterized by hardness and strength; these 
qualities combined in a metal are found to resist wear, sustain 
pressure, and survive shocks. The standard bearing bronzes 



Standard Alloys 103 



range in copper from 82 to 88 per cent, tin 12 to 18 per cent. 
These hard bronzes are still used by many prominent railway 
companies for axle boxes, truck bushes, slide valves, etc., but the 
investigations of recent years may truly be said to have disillu- 
sioned engineers regarding the old popular fallacy, that bearings 
should be made of the hardest mixture possible. In the early 
days of locomotive construction, bearings were purposely made 
of an alloy harder than the steel or iron in the axle, crank shaft 
or journal. A mixture akin to bell metal — copper 84 per cent, 
tin 16 per cent, — was termed "Box Metal," and faithfully used 
to cast axle boxes, because it was found to wear well ; but with 
the development of high speed, high pressure engines, carrying 
heavier burdens, the friction increased at such a rate, necessi- 
tating frequent renewals of expensive forgings, that engineers 
were compelled to modify the hardness of the bearing alloy. 

Nowadays it is the rule to have the bearing made of softer 
material than the journal, and the convenience and economy of 
repairs are found to be considerable. The same principle is 
applied in various ways in ordinary brass foundry practice, as 
for example, in casting the plug for a stop cock, or seat for a 
stop valve, a softer alloy is used than for the cock or valve, so 
that a longer life is insured, and after the wear of the plug has 
reached the limit, a new one may be fitted to the same barrel. 

When phosphor bronze was first introduced as a practical 
alloy some 30 years ago, Kunzel recommended an alloy which 
has been highly successful for bearings, and the frictional parts 
of machines. The alloy referred to consisted of copper, 66^ 
to 91*^ per cent; lead, 4 to 15 per cent; tin, 4 to 15 per cent; 
phosphorus, ^ to 3 per cent. It is worthy of note that the mean 
of these figures gives an alloy with proportions almost equiva- 
lent to the locomotive bearing bronzes in use on many of the 
largest railway systems at the present time. 

Several years ago the Pennsylvania railroad made an ex- 
haustive series of tests with various combinations of copper, tin, 
and lead, in order to determine the best composition which would 
be suitable for its service, and the conclusions drawn from the 
experiments were as follows: 



104 



Practical Alloying 



A simple alloy of copper and tin showed 50 per cent more 
wear than phosphor bronze. 

The phosphorus plays no part in preventing wear excepting 
by producing sound castings. 

Wear increases with the content of lead. 

Wear decreases with the diminution of tin. 

Alloys containing more than 15 per cent lead, or less than 
8 per cent tin, could not be produced because of segregation, 
but it was believed that if the lead could be still further increased 
and the tin diminished and still have the resultant alloy homo- 
geneous, a better metal would result. A very common complaint 
against hard gun-metal as a bearing alloy is "tin spots," that is, 
hard patches due to a localized excess of tin in the alloy. From 

TABLE XI 

Bearing Metal Mixtures 

Phos- Man- 

phorus ganese 

Copper, Tin, Lead, copper, Arsenic, copper, 

Suited for per cent per cent per cent per cent per cent per cent 

Bearings 85 11 .. 4 

Bearings 80 8 8 4 

Bearings 80 10 .. .. .. 10 

Eccentrics 74 8 8 .. .. 10 

Pinions 16 2 .. 1 

Steam cocks 100 12 12 

Bushes 75 11 7 7 

Slide valves 70 10 3 7 .. 10 

Bearings 80 10 7 3 0.80 

the examination of the microstructure of bearing metals, Prof. 
Saveur has come to the conclusion that alloys of copper, tin, 
and lead, are superior to the hard copper and tin mixtures for 
friction-reducing qualities and durability. 

A high place among bearing metals has been awarded an 
alloy containing approximately, copper, 77 per cent, tin, 11 per 
cent, and lead, 12 per cent. Arsenic bronze, that is, ordinary 
copper and tin bronze containing about 1 per cent arsenic, has 
also proved superior to gun metal for bearings. The presence of 
zinc in bearing bronzes is undesirable ; it increases the coefficient 
of friction and produces a fibrous condition of the alloy which 
necessitates careful and regular lubrication. 

A notable bearing metal containing copper, 65 to 75 per 
cent ; lead, 10 to 30 per cent ; tin, 2 to 8 per cent, is sold under 



Standard Alloys 105 



the name of Plastic Bronze. The alloy of copper, 65 per cent ; 
tin, 5 per cent; lead, 30 per cent, has a compression strength of 
15,000 pounds per square inch and is used for the driving brasses 
of locomotives. According to G. H. Clamer, the addition of 
nickel causes the alloy to set rapidly and acts to hold up the lead. 

In Table XT is given a list of some favorite bearing metal 
mixtures, compiled from original sources. 

While these alloys still occupy a prominent place in brass 
foundry practice, the white anti-friction alloys have in great 
measure superseded them. To Isaac Babbitt, the inventor of 
the process of "babbitting" and of Babbitt's metal, belongs the 
honor of being the first to make practical demonstration of the 
utility of soft white metal alloys for reducing the friction of 
bearings and machine parts moving in contact. 

Too much stress cannot be laid upon the fact that the patent 
for the "Babbitt bearing" preceded the patent for Babbitt's metal, 
as it was a greater innovation in the engineering practice of the 
time than the mere compounding of an alloy specially suited for 
bearings. A new principle in machine design, the interspacing 
of the bearing surface, was introduced, and it involved consider- 
able inquiry into the laws of friction. Friction is a factor which 
has to be reckoned with in mechanics ; it is a great dissipator of 
energy, and by it heat is produced. 

Friction has been defined as "that force which tends to stop 
a moving body." The laws of friction as deduced from the 
experiments of Coulomb, Rennie, and others, present a complete 
and sui prising contrast with regard to solids and liquids. With 
the former, friction is (a) proportional to pressure, (b) inde- 
pendent of area of contact, and (c) not greatly affected by the 
velocity of rubbing, while the reverse holds good with the latter. 
The friction of plane surfaces gliding over each other, which is 
the subject immediately under our observation, is influenced by 
the nature of the bodies in contact, and varies in the ratio of the 
weight and pressure of the rubbing parts, and the time and 
velocity of their motions. The ratio obtained by dividing the 
entire foice of friction by the normal pressure is called the coeffi- 
cient of friction. Or to put it another way, the coefficient of fric- 
tion is the ratio of the force of friction to the force pressing the 



106 Practical Alloying 



bodies together. The following are the average values with 
smooth surfaces on the several materials metioned: 

Coefficients of Friction 

Metals on metals, dry 0. 15 to 0. 2 

Metahon metals, lubricated 0.03 to 0.08 

Metals on wood, dry 0.3 to 0.6 

Leather on metals, dry 0.5 

Wood on wood, dry 0.3 to 0.6 

Since the introduction of babbitt metals, the coefficients of 
friction have been considerably lessened. Numerous tests with 
various first-class babbitt metals have shown the following aver- 
ages : Coefficient of friction 0.012, with load of 500 pounds per 
square inch and velocity of rubbing surface 500 feet per minute ; 
compression on 1 cubic inch with loads of from 5 to 10 tons per 
square inch, 0.010 to 0.070; tensile strength about 8,000 pounds 
per square inch ; melting point 450 degrees Fahr. 

The white anti- friction metals are now more numerous than 
the brasses and bronzes which they were originally intended to 
displace. "Babbitt metal" has about lost its individuality and the 
term has been applied to many concoctions which Babbitt would 
have disowned. Things have come to such a pass lately that 
manufacturers have been compelled to classify alloys containing 
over 80 per cent tin as Genuine Babbitt Metal. 

A brief summary of the qualities sought after in alloys 
intended for anti- friction purposes may help us to under- 
stand some of the causes of failure with haphazard 
methods of mixing or buying. The term anti-friction metal is 
based on the fact that certain metals offer little frictional re- 
sistance under a heavy load when in contact with other metals. 
But it must not be thought that high-pressure capacity is the most 
important requirement in bearing metals. The speed, lubrica- 
tion, condition of running, and other factors are sometimes of 
greater moment than the mere burden which the bearing may 
have to carry. However, the characteristics of the white anti- 
friction metals, as a class, may be summed up thus : 

They produce less friction and require less lubrication than 
any other class of metals or alloys. 

Within certain limits they sustain great pressure without 
undue abrasion or compression. They are generally sufficiently 



Standard Alloys 107 



soft to adapt themselves to the bearing surface, and they do not 
readily cut the journal. 

They are comparatively indifferent to the action of sea 
water, acids, etc. 

They have low melting points and are easily manipulated. 

They have small contraction, and they adhere well to other 
metals. In addition to the qualities necessary for ordinary anti- 
friction metal, submerged bearings require to be somewhat neu- 
tral to galvanic action and must offer a high resistance to elec- 
tricity. 

With all these questions under consideration it is little won- 
der that there is great diversity of opinion among engineers 
regarding the most desirable elements and proportions for anti- 
friction metals. The white anti-friction metals may be divided, 
for convenience in distinguishing them, into four classes : 

Genuine babbitt metals, or those alloys having over 80 per 
cent tin in their composition. 

Plastic metals, or those best adapted for pasting purposes. 

Anti-friction metals, or those having lead as a base. 

White bronzes, so-called, or those suitable for sand castings, 
generally having zinc for the base. 

This is by no means the accepted classification of these al- 
loys, but they are growing so numerous that some such classifica- 
tion will soon be necessary. 

Babbitt's metal. — Babbitt's metal, according to the formula 
for which the patent was granted, was a ternary alloy, consisting 
of copper, 3.7 per cent, antimony, 7.4 per cent, and tin 88.9 per 
cent. It was made by the good old-fashioned method of melting 
a portion of the components separately, producing what is known 
as "hardening," or "temper," melting the quantity of tin required 
to complete the alloy and adding in the necessary proportion of 
hardening. 

The best alloys are still made in this manner, irrespective 
of the metal used as a base. The phenomenal success of babbitt 
metal as a friction-reducing substance did much to promote the 
efficiency of modern machinery, and it was to a great extent in- 
strumental in developing speed and economy of power. But no 
alloy made for a special purpose could be expected to possess the 



108 Practical Alloying 



same properties under altered conditions, hence the call for modi- 
fications of Babbitt's formula to meet the views of progressive 
engineers and to keep pace with the economies of modern engi- 
neering. Much study has been given to the metals in their 
relation to friction. 

Some years ago Prof. Goodman made a series of investiga- 
tions to determine the effect on the frictional resistance of minute 
additions of other metals, to a lead, tin and antimony alloy. He 
discovered that by the addition of from 0.03 to 0.25 per cent of 
bismuth, the alloy acquired an almost incredible increase of anti- 
frictional qualities, while a similar admixture of aluminum had 
the reverse effect. Some of the anti-friction metals, though sup- 
posed to be the same, gave frictional results differing by as much 
as 100 per cent. Analyses of the samples showed that the prin- 
cipal constituents were present in about the same proportions, 
but that there were differences in the amount of impurities 
present. Very minute quantities of some elements showed a 
marked effect on the friction — some increasing and others dimin- 
ishing it — and further investigation proved that those elements 



(Atomic Weight \ 
Specific Gravity/ 



of low atomic volume, f ~ rz — ~ r— B increased the fric- 

\ Specific Gravity/ 

tional resistance, while those of high atomic volume decreased 
it, provided that they were present in small and definite pro- 
portions. 

The addition of 0.1 per cent of aluminum, which has an 
atomic volume of 10.6, produced 30 per cent increase in the 
frictional resistance, while the addition of bismuth, which has 
an atomic volume of 21.1, immediately reduced the friction. It 
would seem, therefore, that some elements, as bismuth, arsenic 
or phosphorus, have a beneficial influence on anti-friction metals, 
while other elements, as aluminum, iron or nickel, have a con- 
trary effect. Table XII enables us to contrast the properties of 
the metals in relation to friction. 

Assuming that the viscosity of liquids is conducive to fric- 
tion, and low specific heat combined with fusibility and hardness 
are desirable qualities in lining metals, we have sufficient reason 
for considering that those metals which do not run freely, as 
aluminum, copper, zinc, and those which assume a pasty con- 



Standard Alloys 



109 



dition near to the point of solidification, as aluminum and iron, 
are less suited for reducing friction than metals possessing good 
flowing power, along with these other qualities. The benefits of 

TABLE XII 

Properties of Metals in Relation to Friction 



Heat con- 








Specific 


Atomic 


ductivity 


Hardness 


Viscosity 


Fusibility 


heat 


volume 


Copper 


Antimony 


Aluminum 


Tin 


Aluminum 


Bismuth 


Tin 


Bismuth 


Copper 


Bismuth 


Iron 


Antimony 


Iron 


Iron 


Antimony 


Lead 


Zinc 


Lead 


Lead 


Zinc 


Iron 


Zinc 


Copper 


Tin 


Bismuth 


Copper 


Zinc 


Antimony 


Tin 


Aluminum 




Tin 


Lead 


Aluminum 


Lead 


Zinc 




Lead 


Tin 


Copper 
Iron 




Iron 
Copper 



arsenic in lead, phosphorus in bronze, bismuth in solders, and 
mercury in bismuth alloys or fusible metals, in increasing fluidity, 
and fusibility, are already well known, but the benefits derived 
by combining metals of high atomic volume and low specific heat 
and conductivity are not generally understood. 

Taking the metals as arranged in the above table, a glance 
may show that if heat conductivity only had to be considered in 
selecting metal for anti-friction purposes, bismuth, the lowest 
conductor of the series, would best meet the requirements; if 
hardness was the indispensable condition, then antimony would 
be the ideal metal, and so on through Table XII, reading the 
columns from left to right. 

The physical structure of metals and their chemical affinities 
combine to regulate the production of alloys conducive to the 
lowering of friction. Bismuth, we have seen, possesses many 
excellent qualities of this kind, but it lacks cohesion, and is there- 
fore unsuitable as a base for a bearing alloy. Lead makes a good 
second to bismuth in three of the most desirable properties, heat 
conductivity, fusibility and atomic volume, and but for its known 
softness, which causes it to spread and flow under pressure, it 
would, by itself, make a first-class anti-friction metal. The anti- 
friction alloys having lead for their base are daily increasing. 
They are hardened and have their melting points regulated to 
suit various conditions, by admixtures of copper, antimony, tin, 
bismuth or arsenic. In the words of an advertisement, "they 
have a graphite-like surface which is partially self-lubricating." 



110 Practical Alloying 



Prof. A. Humboldt Sexton declared at a public lecture in the 
Technical College, Glasgow, that the extraordinary success of the 
well-known "Magnolia Metal," was due chiefly to the combina- 
tion in suitable proportions of the metals — lead, antimony and 
bismuth. 

Impurities in bearing mixtures. — We have already seen that 
a very slight amount of impurity in the alloy used for bearings 
may increase the coefficient of friction and cause untold mischief. 
As all the commercial metals contain more or less impurities, it 
becomes manufacturers to guard against those elements which 
are known to increase friction, as aluminum, iron, nickel, and to 
be careful that the method of making up the alloys does not add 
to the content of impurities. Some firms announce that their 
metals "can be melted in an iron pot and they do not deteriorate 
by remelting." Such a statement is either an evidence that zinc 
or phosphorus are not contained in the alloy (if they were they 
would attack the iron), or else it contains one of those ingenious 
phrases put out by advertising experts to sell the goods. 

Crucible melting is acknowledged to give the best results, 
and if large quantities are required, a furnace with a silicious 
lining is preferable. Enough has been said to show the need for 
considering the properties of the metals and the peculiar con- 
ditions which go to make good anti-friction alloys. 

Compounding anti-friction alloys. — The salient points to be 
observed in compounding anti-friction alloys are condensed as 
follows : 

Anti-friction alloys are better and more economically mixed 
by the "bath" system, or by means of "hardening," than by the 
direct fusion of the components. 

They should not be heated to redness — the proper heat may 
be judged by inserting a pine stick; it should smoke or singe, but 
not burn. 

If the alloys are overheated, antimony and zinc are de- 
creased by volatilization, and a greater amount of separation of 
other constituents occurs in the process of solidification. 

For all around excellence, genuine babbitt metals are to be 
commended. 

For a cheap metal to give good wear, alloys with zinc in 
the base give satisfaction, if properly lubricated. 



Standard Alloys 111 



For a metal requiring little attention at high speeds, alloys 
having lead in the base are the most suitable. 

Plastic metals should contain little antimony, as that metal 
forms a grit on the bolt or pasting-iron, and prevents the flow of 
the alloy. 

Aluminum and nickel are altogether unsuitable elements in 
anti-friction alloys. 

Beware of alloys whose virtues are advertised in the neg- 
ative form. 

A metal with a low coefficient of friction runs cooler and 
requires less lubrication than one with a higher coefficient. 

The temperature of fusion is lowered by about one-seventh 
in ordinary practice; this is due to the pressure. 

Traces of impurities have not the far-reaching effects in 
brass alloys that they have in gun metals or anti-friction alloys. 

Arsenic tends to crystallize other metals; it also promotes 
the union of other metals that would otherwise be difficult to 
mix. 

Phosphorus prevents blistering, promotes fluidity and in- 
creases hardness. 

Manganese is recommended for hydraulic machinery, or 
where chemical solutions give rise to corrosion with the ordinary 
alloys. 

Powdered sal-ammoniac is the best flux for babbitt metals. 

Sawdust is a good protection for the alloys in the molten 
state. 

A metal, not an alloy, which takes a high polish is better 
for linings than one which takes a dull polish. This would indi- 
cate the need for a close-grained metal. 

Anti-friction alloys are manufactured in three grades or 
degrees of hardness, to suit the varying load, speed and duty of 
machines. In testing the comparative values of alloys as anti- 
friction metals, these things should be fairly considered. Often- 
times destructive tests are made in laboratories, with the object 
of fusing ihe metals by abnormal pressures and conditions. The 
conclusion to be drawn is that the metal which sticks or fuses 



112 Practical Alloying 



first is the worse anti-friction substance. This is hardly a fair 
test, as it neglects to consider the duty for which the metal is 
designed. The only practical test for such metals is the co- 
efficient of friction in actual working conditions. 

Dual alloys. — The early attempts to produce anti-friction 
metals were mostly dual alloys, 10 per cent compounds of copper 
in tin, copper in zinc, antimony in tin, or antimony in lead; but 
the limitations of these alloys were far from satisfying the gen- 
eral requirements. Dual alloys, therefore, are an unimportant 
class, entirely out of favor, except in one or two special cases, 
as lead and antimony, called antimonial lead, for submerged light 
bearings or chemical plant, or tin and antimony, for gas plant 
machinery. An example of the latter used by a large firm of 
meter manufacturers is composed of tin, 75 per cent, antimony, 
25 per cent. For light machinery running at ordinary speeds an 
alloy of lead and arsenic, known as "shot" metal, makes a splen- 
did anti-friction metal. Table XIII gives a selection of the best 

TABLE XIII 

Some of the Best Babbitt Alloys 



Copper, 


Tin, 


Antimony, 


Lead, 


Zinc, 


Bismv 


ith, • 


Name. 


per cent 


per cent 


per cent 


per cent 


per cent 


per cent 




3 8 


78.56 


11.8 


6 








Navy bronze No. 1 


8 


83 


9 










Admiralty special 


1 80 


64.70 




i 


33.35 






Parsons 


4 


35 


17 


44 








Navy bronze No. 4 


7 


80 


2 


10 




i 




Plastic metal 


18 


2.5 


4.5 


75 






White brass No. 1 


3.64 


22.14 






74.22 






White brass No. 2 




42 


12 


46 








Lining metal 


2 50 




16.43 


80.24 




0. 


76 


Universal bearing metal 




48 


4 




48 






Marine bronze 


7 5 


84 


7.5 






l 




Motor bronze 


8 


75 


17 










Locomotive bearings 



alloys derived by analysis or from the formulas of the makers. 
These alloys are all of proven excellence, and, although they have 
not been set down in the order of their merit, they have been 
selected from the very best authorities and practice in the engi- 
neering world. 

"Babbitt, the man and the metal. — Babbitt, Isaac, American 
inventor, born Taunton, Mass., July 26, 1799; died May 26, 1862. 
Served an apprenticeship to the goldsmiths' trade and early be- 
came interested in the production of alloys. In 1824 he manufac- 
tured the first britannia ware in the United States. In 1839 he 
discovered the well known anti-friction metal, for which the 



Standard Alloys 113 



Massachusetts Charitable Mechanics Association awarded him a 
gold medal and congress subsequently voted him a pension of 
$20,000." 

The insertion of this excerpt from the Encyclopaedia Ameri- 
cana may serve to describe the man who introduced that most 
popular alloy of the 19th century — babbitt metal. Many people 
have hazy notions of Babbitt, babbitt metal and babbitting. 

Babbitting, or the lining or interspacing of bearings with 
anti-friction metal has done more to increase the speed and 
economy of modern machinery than any other single process or 
practice in engineering. 

Remember, Babbitt manufactured britannia ware and bri- 
tannia metal is an alloy of tin hardened by antimony and copper 
Babbitt's metal, therefore, was purely and simply a britannia 
metal, and when he had finished with the making of it, it con- 
sisted of tin 88.9 per cent, antimony 7.4 per cent and copper 
3.7 per cent. The figures give us no information about the 
method of combining the metals and that is the most important 
thing in the production of alloys intended to undergo mechanical 
treatment. The improvements in the modern bronzes are as 
much due to correct methods of combining the metals as to the 
introduction of new elements. It is recognized nowadays, that 
the mere melting and mixing of metals together, regardless of 
their chemical qualities, does not conduce to the highest ex- 
cellence in the combination. The direct melting of the metals to 
produce an alloy of more than two metals is a crude process, 
wrong in principle and generally unsatisfactory in the final result. 
The use of "hardening," "remelting," "temper" and "fluxes" must 
be understood in order to get the best results from babbitt metal. 
Even the order in which the metals are melted and blended is of 
some importance. The proper course is always to make a 
"hardening" for alloys of metals showing disparity in fusibility 
and specific gravity. Babbitt's "hardening" was made by melting 
copper 4, then adding gradually tin 12, antimony 8, and finally a 
further addition of tin 12. To make the "lining" metal 72 parts 
of tin was melted and the 36 parts of "hardening" dissolved 
therein, so that the alloy was made at a low temperature — prac- 
tically at the heat of melted tin. 



114 Practical Alloying 



Overheating anti-friction metals. — Overheating is a fruit- 
ful cause of dissatisfaction with the wearing and working quali- 
ties of anti-friction metals. The effect of high temperatures on 
metals of low fusibility is always harmful, more especially if the 
metals have a tendency to crystallize. In cooling, the refractory 
combinations (copper, antimony, tin) set first, leaving the more 
fusible combinations (tin, antimony, copper) to solidify on the 
surface. That is why in the directions for using genuine babbitt 
metals we are told to cast the working face of the bearing down- 
wards if possible, and to avoid high temperatures and slow cool- 
ing. The latter conditions produce bigger crystals and a greater 
separation of the constituents in the alloy weakening its cohesive 
force and increasing the coefficient of friction. 

The properties which make babbitt metal so valuable are its 
power of accommodating itself to a hard unyielding surface, its 
capacity for taking a polish, its power of resisting certain chem- 
ical influences, and its low melting point. Genuine babbitt metal 
will not cut, scratch nor heat the journal, and after being in use 
for some time, the bearing takes a glittering appearance on the 
surface. But all that glitters is not babbitt! The variations in 
the genuine babbitt metal are limited, but the commercial grades 
sold for babbitt metal are endless and the prices sometimes 
prove that tin is regarded as a luxury. 

During the years of my apprenticeship Babbitt's patent 
metal was the only thing available for lining bearings, etc., but in 
25 years many changes are possible. It was found that babbitt 
alloy was greatly improved as a self-lubricating metal for fast 
running light machines, when a portion of the tin was replaced by 
lead. Further experience brought out the truth that properly 
hardened lead was equal to hardened tin as a metal for anti- 
friction purposes. 'Twas then the flood arrived! 

For some years it rained anti-friction metals. They were 
registered under all sorts of fancy titles. Beginning at Zero, 
they worked right through the Glacier-cum-Glyco period into the 
heart of Greek mythology. By comparisons the staying powers 
of Atlas, the strength of Hercules and the defiance of Ajax were 
set at nought. The Bull and the Bear were driven Tandem on 
the market, while the Stone and Rock Bronzes understudied the 




Fig. 11 — Melting babbitt metal in a 
500-pound crucible in a pit furnace 



Fig. 12— Method of handling the 500- 
pound crucible when pouring 
the metal 





Fig. 13— Cast iron gas furnace and ladle for babbitt metal 



Standard Alloys 115 



Parsons. At the sign of the White Ant the Navy casts Anchor 
and upholds the Crown. There are too many of them; we shall 
soon want a standardizing bureau for the anti-friction alloys, — 
registered and unregistered, equal to babbit, better than babbitt 
and — Babbitt. 

How to make babbitt metal. — Now, if you should happen 
to want the best babbitt or anti-friction metal that can be made, 
make it yourself thus : 

Select the purest metals that can be had and the most suit- 
able formula for the duty of the alloy; make a preliminary mix 
of the refractories in a plumbago crucible and pour it out for 
"hardening." Melt the metal which form the basis of the alloy, 
(it may be tin, lead, or zinc,) and dissolve the hardening therein, 
at a gentle heat, using sawdust, tallow, or powdered sal- 
ammoniac for a flux. For making a large quantity in the ordi- 
nary brass furnace make a cast iron crucible two inches smaller 
than the diameter of the furnace; lower it into the furnace and 
lute round as shown in Fig. 11. Fig. 12 shows how conveniently 
such a pot may be handled. The capacity of this one is 500 
pounds. A more uniform grain may be had from a good sized 
melt than is possible with a small lot. One word of caution is 
needed here. Zinc should not be melted in an iron pot, but if 
melted in a plumbago crucible it may be poured and mixed with 
the other components of the alloy already melted in the pot. 

Another very convenient furnace for remelting all kinds of 
babbitt and anti-friction alloys is shown in Fig. 13. This style 
of furnace is not recommended for making the alloys unless 
where "hardening," already prepared by melting the refractory 
metals together, is used ; but it is handy for lining metals which 
are poured with a hand ladle, and it may be moved about to any 
place where there is a gas union. 

The utility of babbitt metal is not to be gaged by the number 
of cents it costs per pound. A cheap babbitt, lead or zinc base, 
well made, may give better service than a costly mixture which 
has been carelessly blended. Besides the commercial grading of 
metals by number or title is like the private marks of retail mer- 
chants, unintelligible to the outsider. Generally the grades are 
for (1) light loads and high speeds, (2) medium loads and 



116 Practical Alloying 



moderate speeds, (3) heavy loads and slow or moderate speeds, 
and (4) heavy loads and high speeds. Such grading is reason- 
able, for the hardness of the alloys increases with the numbers, 
and price does not count. The time for selling alloys by analysis 
is not yet, but "Come it will for a' that." 

To sum up, babbitt metal is essentially a tin alloy, but mod- 
ern engineering practice and commercial usage favors the con- 
tinuance of the name to all metals capable of the same duty as 
babbitt. Hence we get three series of babbitt or anti-friction 
metals: (1) the tin series, (2) the lead series, (3) the zinc 
series. Tin is the most polishable of the soft metals, and it 
alloys readily with any of the useful metals employed for mini- 

TABLE XIV 

Special Babbitt Mixtures 

For lining Tin, Lead, Zinc, Antimony, Copper, Bismuth, 

per cent per cent per cent per cent per cent per cent 

Dynamos, high speed 

Marine engines 

Eccentrics 

Submerged bearings 

Main bearings 

Slides, thrusts 

Railway trucks 42 

Axle boxes by analysis 

Anti-acid metal by analysis 

Plastic metal 

Genuine babbitt (hard) 

Genuine babbitt, No. 2 

Universal bearing metal 

Anti-friction castings 

mizing the friction of machinery ; it has been made the basis of 
the best anti-friction alloys. Lead is undoubtedly the best anti- 
friction medium among metals, but it lacks a great deal of stiff- 
ness to stand up to the work. Copper is the ideal bond for zinc 
alloys, and zinc is the most expansible and durable of metals. 
Zinc babbitts cast well, wear well and fit snugly to the bearing. 

Owing to its highly crystalline structure, antimony, the prin- 
cipal hardening element, should not exceed 20 per cent, as it is 
apt to separate and rub out of the alloy. Seventeen per cent has 
been fixed as the limit by an eminent authority. 

There are critical points in many alloys of the common 
metals. Lead and tin may be united in any proportions, but the 
hardest alloy of the two metals is obtained when they are present 
in the ratio of 4 and 6 respectively. 



88 






8 


3.5 


0.5 


77 


17 




3 


3 




5 


78 




15 


2 


0.25 


40 


' 48 - 




10 


2 




34 


44 




16 


6 




65 




30 


2.5 


2.5 




42 




56 




2 




74.22 


13.50 


1.80 


6.55 


3.60 




78.84 


14.75 




trace 


3.70 




80 


10 




1 


8 


1 


80 






10 


10 




83 






9 


8 




6 


78 




16 




0.25 


24 




80 




4 





Standard Alloys 117 



The mutual relations of the metals determine the mechanical 
properties of the alloys. Zinc and antimony are too much alike 
to be used simultaneously and tin alloys, without copper, are 
apt to spread under heavy loads. Due to its poor affinity for 
lead and tin and its low atomic volume, aluminum is not a suit- 
able metal for anti-friction alloys. Bismuth, on the contrary, is 
a decided advantage up to about 1.5 per cent. This metal has 
been freely used in the production of some modern alloys, 
notably those with low fusibility, low contraction and high 
atomic volume. In Table XIV are given some special mixtures 
which have given complete satisfaction for the duty stated. 

Lastly, we have the mixtures of a manufacturer representing 
four grades as given in Table XV. 

In each case the metals represented by the figures, 7, 17 and 
6 constitute the "hardening." These are what are termed copper 







TABLE 


XV 










Grades 


No. 1 
per cent 




No. 2 
Per cent 


No. 3 
per cent 


No. 4 
per cent 


Tin 

Zinc 




77 

17 

7 

6 




77 
17 

7 

6 


17 

77 

7 

6 


77 
17 
6 

7 



hardened alloys, — the copper content being over 5 per cent. This 
series is worthy the attention of all who are seeking for cheap, 
serviceable anti-friction metals. The composition of a special 
manganese babbitt follows : Tin 80 per cent, lead 10 per cent, 
antimony 7 per cent and manganese-copper 3 per cent. 

An anti-friction paste, recommended for fans, etc., running 
at high speed, follows : Tallow, 6 parts ; plaster of paris, 3 parts ; 
beeswax, 3 parts ; blue butter, 1 part ; plumbago, 1 part. Melt 
together and allow to cool before using. 



IX 



FOUNDRY MIXTURES 



IN striking contrast to the simplicity and exactness of the 
formulas specified for standard alloys, the mixtures used 
in brass foundries generally are variable. The ordinary 
foundry metals are therefore of unequal properties, and 
the methods employed in their manufacture are sometimes of 
doubtful value. Commercialism seems to dominate the brass in- 
dustry to the prejudice of its products. There is more fictitious 
valuation permitted with brass founders' alloys than would be 
tolerated in any other department of the foundry business. Brass 
has become a name signifying a metal yellow in color. Gun 
metal is a convenient term for alloys of more coppery appear- 
ance, and in these days when things are being sold, which, ac- 
cording to the advertisements "operate to increase the chemical 
affinity between the different elements of a mixture, and tend to 
determine the copper or higher colored elements to the surface," 
any old metal may be converted into respectable, colorable gun 
metal. All alloys are the outcome of experiment and research, 
and as improvements in the manufacture of alloys have had to 
keep pace with other advances in the metal industries, many proc- 
esses, having no bearing on the intrinsic merits of the metals, 
have been adopted in general foundry practice. For example, to 
avoid the loss due to remelting, many excellent gun metals are 
made by introducing into molten copper, old metals of known 
proportions, as yollow brass, bell metal, plumbers' solder, etc. 

The art of mixing old metals and producing castings of good 
uniform grades requires a deal of skill, experience and good 
judgment. So many things may be overlooked in passing a heap 



Foundry Mixtures 119 



of scrap. Some pieces may appear clean and even in the grain, 
yet the effect of a very small percentage of either antimony, or 
aluminum in them would be to ruin the whole mixture for many 
kinds of castings. Every firm has its own methods of manufac- 
ture and its own stock-in-trade of mixtures suited for particular 

TABLE XVI 

H. G. M. railway, 

"Ash" Mefal, M. Ingots, axle bars, 

Metal per cent Per cent per cent 

Copper 71.60 75.55 82.75 

Tin 5.00 1.45 13.04 

Zinc 5.42 20.80 3.81 

Lead 17.55 2.00 

Antimony 0.40 0.35 

Total 99.97 99.80 99.95 

classes of work. Every foundry foreman, too, has his favorite 
mixtures and a note book which he prizes more than a whole 
technical library. 

The need for this note book will be most apparent to those 
who best understand the delicate and complex nature of certain 
alloys and the alternative methods of making them. The blend- 
ing of metals is as much an art as the treating of foods or fabrics, 
and the recipes in the first mentioned business are equally im- 
portant. The metal-mixer who is called upon to produce alloys 
to specification, from old metals, must work up a system of aver- 
ages. For the purposes of the mixtures in Table XVI, yellow 
brass was reckoned to average, copper two-thirds, zinc one-third, 

TABLE XVII 

Standard Alloys From Mixed Metals* 



J5 a S 

■o J i ° 



o 


a 




"o 




K 










u 


H 


J 


>H 


« 




tf 


£ 




U 


53 






18 


28 




Copper 87 


Tin 8 


Zinc 5 


Merchant ship 


20 










100 


Copper 88 


Tin 10 


Zinc 2 


H. M. S. "Dido" 


84 


11 




4 






Copper 88 


Tin 12 




Fire Brigade Hydrant, Edinburgh 


41 






20 


32 




Copper 14 


Tin 1 


Zinc 1 


Trinity Marine Board, London 


1 




1 






10 


Copper 81 


Tin 10 


Lead 9 


Glasgow Corporation Sewage Plant 



*A11 of these metals stood the physical tests required from the specified alloys, 
notwithstanding deviations as great as 1.7 per cent from the quantities stated in 
the specifications. 



120 



Practical Alloying 



bell metal to contain 18 to 20 per cent tin, and the analyses of 
mixed metals in stock in the foundry where these alloys were 
made as given in Table XVI, were sufficient guide to attain satis- 
factory results as shown in Table XVII. 

Numerous examples might be given of ordinary brass found- 
ers' alloys being made from a collection of old metals but a few 
will suffice to show how much may be done by studying the 
characteristics and contents of the scrap heap. 

Brazing metal. — Brazing metal may easily be made by add- 
ing to melted copper from 1 to 3 times its bulk of brass tubes 
or sheathing. A common practice in making cheap gun metals 
is to melt a quantity of mixed brass scrap and add an equal 
quantity of standard gun metal, (Copper 9, tin 1). An excellent 



TABLE XVIII 

Specimen Foundry Mixtures Containing Scrap or Old Metals 































































M 


u 


s 


o 


« 




v 
a 

a. 
o 


c 


S S 


13 


e 

< 






O 


a 


U 


H 


»J >J 


;* 






; 


J 


z 


20 




m 


15 










Cock Metal 


28 


1 




10 








7 


Red Metal 


16 


1 


2 










4 


Red Metal 


16 


2 


1 


6 










Pan Metal 


16 


1 


3 


6 










Pan Metal 


64 


8 




6 










Screw Metal 


16 






8 


1 








Screw Metal 


16 


1H 




2 










Bolt Metal 


93 


5 


2 










10 


Steam Metal 


20 


2 


1 


10 










Steam Metal 


16 


134 


1 


4 










Steam Metal 


40 






30 




30 






Gun Metal 


16 


2 




2 










Gun Metal 


64 


15 




1 










Bell Metal 


64 


4 


1 


8 










Art Metal 


32 


m 


2 








32 




Bush Metal 


32 


5 


1 


5 










Bush Metal 


20 


3 




14 










Bush Metal 


50 








10 to 30 


100 






Bush Metal 


16 


1 






1 




10 




Bush Metal 


2 




1 




4 


18 


6 


4 


Bush Metal 



anti-friction alloy for high speed, low pressure machines results 
from the following mixture, lead shot, 100 parts, antimony 6 to 
10 parts. The arsenic in lead shot has a great influence on the 
anti-friction properties of lead-antimony alloys. 

Another alloy in which lead shot figures is known as "Ajax" 
bronze- -copper 100 parts, tin 12^2 parts, arsenic lead 12^ parts. 



Foundry Mixtures 121 



This is an excellent bearing metal ; it is also well suited for cocks 
and fittings for chemical plants. 

The most reliable anti-acid metal is made from copper 3 
parts, antimonial-lead 1 part. Good steam metal may be made 
by simply adding 15 per cent plumbers' fine solder to molten braz- 
ing meial. This is a convenient way to use up old flanges. Other 
examples of mixed metals being used for practical combinations 
will be found in Table XVIII. The qualities are given in round 
figures, and may be read as pounds, or as parts in ratios suited 
to the capacity of the crucible or the work to be cast. It is 
customary in brass foundries to have the composition or alloying 
metals, fixed in relation to the pound of copper, therefore most 
of the figures are either multiples or fractions of sixteen, the 
number of ounces in the pound avoirdupois. 

Many brass founders run away with the notion that the 
mixture is everything and forget that the melting practice is the 
most important part in the mixing of metals. Some pride them- 
selves on possessing certain recipes which they imagine give 
them advantages over their competitors. Experience is the best 
guide, and careful attention to details the best recipe, for the 
blending of metals into alloys. Foundry alloys are mostly regu- 
lated by the metals available and the prices obtainable for cast- 
ings. The relative weights of the metals entering into an alloy 
are of some importance in the final value of the castings. 

The addition of aluminum in an alloy is sometimes an econ- 
omy, just as the addition of lead — the cheapest adulterant, is 
frequently made a means of gain. The high or low specific 
gravity of the alloy makes a difference in the price or the profit. 

Typical brass founders' alloys. — The general public has an 
idea that the brass trade is one, at least, in which there can only 
be a limited amount of trickery. In some quarters, anything hav- 
ing the color of brass will suit, even if it is mainly zinc; and in 
others, a metal having the color and fracture of gun metal is as 
good as the best. Yellow brass and gun metal are probably the 
two most prominent alloys on the brass founders' list, but they 
have ceased to be the typical metals they were in the good old 
days before brass founders knew more than one way of making 
them, unless in shops working to standard formulae and require- 



122 Practical Alloying 



ments, or where specifications and tests are part of the contract. 
I do not mean to infer by this that the brass founder is degenerat- 
ing, or that he has lost his cunning in mixing the alloys, but 
rather that the exigencies of trade, price-cutting and competition, 
have left him no other possible way out than by a skillful manipu- 
lation of the metals within the limits of his customers' specifi- 
cations. The ideal has almost been attained in iron founding; 
cast iron will in all likelihood, soon be bought, mixed, and sold, 
universally, by desirable chemical standards, and the mechanical 
tests required will be obtained by methods of melting and cast- 
ing. Surely if it is a desideratum to seek for exact proportions 
of the elements in various grades of cast iron, it is none the less 
necessary in different qualities of brass. It used to be that the 
quantities of zinc or tin periodically consumed were a sufficient 
index of the character of the work done in a brass foundry. 
Nowadays, when the brass refiner is a power in the land, and the 

TABLE XIX 

Specimen Air Furnace Charges, Containing Scrap and Old Metals 



_u 6 $ ¥ ? X & & 

Centrifugal pumps 
Ciculating pumps 
Fluid, close grained 

5 

30 pounds phosphor-copper added 

4 Good red metal 



Pumps 10 50 

Pumps 4 10 8 

Liners 10 25 16 2 

Liners 5 10 . . 10 

Propellers 6 24 2 

Tube plates 16 4 6 

Brasses 4 10 3 

Stern tubes 16 8 16 2 

Brasses 1 10 1 .. Sugar mill bearings 

Steam Pipes 3 3 3 9 .. .. Mixed borings, 140 pounds 

Sluice Valves 22 4 22 .. .. Fluxed with 18 pounds old bottles 

habit of buying mixed metals, ingot, and scrap, has grown to be 
recognized as a necessary evil, the line cannot be drawn so easily 
which separates brass and gun metal, or the legitimate use of the 
cheaper metals in the manufacture of brass founders' alloys. 

Perhaps we cannot better illustrate this point than by giving 
the reply of a foreman brass molder, who, when asked to pur- 
chase a recent book dealing with brass founders' alloys, said: 



Foundry Mixtures 



123 



"What do I want with a book of mixtures, when all I get to mix 
is a bar o' lead and a barrel o' sojer's buttons?" Fortunately, 
this is an extreme case, and the resources of the average brass 
founder are not confined to such puerile commodities. Never- 
theless there is a suggestiveness about that "bar o' lead," which 
will appeal to the engineer or trader handling either marine or 
jobbing brass castings. It is due to the refiner to say that he has 
in great measure educated brass founders and opened their eyes 
to new possibilities in the matter of serviceable alloys, high- 
tension alloys and alloys containing the base metal. The staple 
product of the brass refiner in Great Britain is known to the 
trade as Ash metal. This is a low grade brass containing all 

TABLE XX 

Specimen Foundry Alloys, from New Mexals, in Pounds 



















d 


















5 










s 


>. 
















9 


a 






a •? 


a, 
a. 



U 


c 


a 


•0 


.a 
a 

a 
< 


| 

a 

< 


M 
u 

z 


a 

%•* 

t— 1 


Phosph 
Used fo 


16 


1 


1 


1 










Cocks, valves, etc. 


80 


6 


8 


6 










Marine brasses 


16 


2% 




y*. 








Locomotive brasses 


80 


10 


'io 












Propellers 


80 


8 


4 


"% 










Mill brasses 


16 


1 


1 


2 










Cock metal 


92 


4 


1 


2 










1 Pinion6 

Hydraulic pumps ^r 


95 


4 














82 


11 


3 


'2' 










2 Bearings 


88 


8 




3 










1 Slide valves 


88 


9 


"3 












Gun metal 


17 




15 


"\ 






8 




German silver 


28 




12 


1 











German silver 


45 




30 




2 








Aluminum brass 


4 


110 


48 






"l 






Babbitt metal 


2 


84 


112 












Babbitt metal 


67 


1 


40 










2 


Delta metal 


10 




80 




'3 








White brass 


80 


8 


4 












Gun metal 


4 


35 




44' 


91 


17 
1 






Navy bronze 
8 Art metal 


140 


12 














2 Phosphor bronze 


55 


1 


'46 








'i 


'3 


Manganese bronze 


100 


12 


8 












Spring metal 



sort of impurities; it is reduced from skimmings, furnace ashes, 
buffings, chips and sweepings, and when a sufficient quantity 
for a heat has been washed it is smelted and tested to see how 
much lead or zinc it will carry before being run into ingots for 
the market. Ash metal has really no claim to the name of brass 
unless for its color, and then it sometimes might with equal jus- 



124 Practical Alloying 



tice be termed German silver, and no self-respecting brass founder 
would ever dream of using it for castings by itself. He generally 
mixes some other metal with it to give it body, or else he uses it 
as a cheap reliable adulterant in new metal. To the credit of the 
refiner it must be said, he makes no professions about his Ash 
metal other than that it is cheap. The following is an analysis 
of a regular Ash metal sold in Glasgow in 1900: Copper 57.08 
per cent, tin 1.23 per cent, zinc 25.65 per cent, lead 14.12 per 
cent, antimony 0.42 per cent, iron 0.61 per cent. 

Every well managed foundry has a system of collecting and 
using its own scrap, borings or surplus metals, for the regular 
grades. Most difficulty is experienced in connection with "for- 
eign" scrap, or metals which have to be judged by appearance 
or by mechanical tests. Alas ! appearances are oftentimes deceiv- 
ing and even mechanical tests may be misleading as to the blend- 

TABLE XXI 

Constituents and Range of Basis Elements in Typical Brass 
Founders Alloys 

Per cent of 
Name of alloy. Constituents. Basis metal average 

content 

Brass Copper and zinc Copper 60 to 75 

Brazing metal Copper and zinc Copper 80 to 90 

Bronze Copper and tin Copper 84 to 94 

Bell metal Copper and tin..._ Copper 78 to 84 

Gun metal Copper, tin and zinc Copper 80 to 90 

Steam metal Copper, tin, zinc and lead Copper 80 to 90 

Cock metal Copper, zinc and lead Copper 75 to 90 

Phosphorus bronze Copper, tin and phosphorus Phosphorus. . . .0. 25 to 3 

Aluminum bronze Copper and aluminum Aluminum 2 to 10 

Aluminum brass Copper, zinc and aluminum Aluminum 2 to 5 

German silver Copper, zinc and nickel Nickel 15 to 25 

Delta metal Copper, zinc and iron Iron 1 to 3 

Manganese bronze Copper, zinc, iron and manganese . . . Manganese . 5 to 5 

Silicon bronze Copper, tin and silicon Silicon 0.5 to 2.5 

Hard solder Copper and zinc Copper 48 to 55 

Soft solder Tin and lead Tin 50 to 75 

Anti-friction metal, grade I Tin, antimony and copper Tin 80 to 90 

Anti-friction metal, grade II ... . Zinc, tin and copper ; . . . . Zinc 60 to 80 

Anti-friction metal, grade III. . .Lead, antimony and copper or tin. . .Lead 75 to 82 

Britannia metal Tin and antimony Antimony 8 to 10 

Type metal Lead and antimony Antimony 10 to 20 

Fusible metal Bismuth, lead and tin Bismuth 15 to 40 

ing or alloying properties of a metal which behaves decently if 
taken by itself. In the examples already given, the custom of 
making alloys from mixed metals is exemplified, but the analyses 
furnished with these mixed metals made it easy to graduate the 
components in the finished alloy. This is the exception : the rule 



Foundry Mixtures 125 



in most foundries is to take any old metal that comes along and 
work it in, (lavishly or sparingly, according to quality) with the 
metals carried in stock. 

Mixtures for chandelier work. — The most modern designs 
for chandelier work have brass, wrought iron and copper in com- 
bination. Brass is generally the foundation of the color scheme 
and many plain and ornamental castings are necessary for the 
completion of the design. The whole of the work is lacquered 
when it is finished. For the most part it is left bright but some- 
times the plain parts are bronzed and relieved at suitable places 
by burnishing. Castings for the latter are usually made from the 
ordinary yellow brass, two and one alloy. 

For the finer ornamental work which is to finish bright and 
be dipped in acids to heighten the effect of ornamentation and 
color contrasts, only dipping metal, or fine brass alloys may be 
used. Such alloys range in copper from 70 to 85 per cent and zinc 
from 15 to 30 per cent. The higher the percentage of copper the 
deeper the color of the brass, and if a paler color is required than 
can be had with only copper and zinc in the mixture, from one 
to three per cent of aluminized zinc may be added to the last 
named quantities. 

Small additions of any metals having a tendency to harden 
or close the grain of the alloy will give a higher polish with the 
burnisher. Nickel, manganese, aluminum, tin, arsenic, phos- 
phorus, each have this effect, but with the exception of aluminum, 
not more than 0.5 per cent should be present in the alloy. On 
the other hand the presence of such impurities as lead, iron or 
antimony, would be fatal to a brilliant finish in the dip. The 
main point therefore in making a successful dipping metal is to 
use only the purest metals that can be had. Remelted zinc will 
not do for a first-class dipping mixture ; it always contains the 
impurities mentioned. Two first-class mixtures used by Birming- 
ham (Eng.) founders are: Copper 19 pounds, zinc 6 pounds, and 
copper 30 pounds, zinc, 12 pounds, tin *4 pound. 

A brass mixture for dipping can only be cheapened by in- 
creasing the proportion of zinc and a large class of decorative 
work is run with mixtures containing from 7 to 14 pounds of 
zinc to every 16 pounds of copper, that is to say, the cheaper 



126 Practical Alloying 



dipping metals show from 30 to 47 per cent zinc while the finer 
qualities have only 16 to 28 per cent. 

For variety of color scheme, a beautiful, deep-tinted, golden 
bronze suitable for turned parts, results from a mixture in the 
following proportions: Copper 90 per cent, tin 6^4 per cent, 
zinc 2% per cent, lead 1 per cent. 

Pale Gold Alloy : Copper 72 per cent, zinc 27 per cent, and 
aluminum 1 per cent. 

Dips and lacquers. — To blacken aluminum, clean the metal 
thoroughly with fine emery powder, wash well, and im- 
merse in — 

Ounces 

Ferrous sulphate 1 

White arsenic 1 

Hydrochloric acid 12 

Dissolve and add — 

Water 12 

When the color is deep enough dry off with fine sawdust and lacquer. 

Lacquers are ordinarily of two kinds: alcohol and products 
of alcohol. Good alcohol lacquers consist of shellac, and 
gums of various sorts, to produce colored effects, and are ap- 
plied by heating the brass. The lacquer most commonly used is 
made by dissolving 1 ounce of soluble cotton in a quart of 
amylacetate and thinned with mixture of amylacetate and fusel 
oil to the consistency desired. 

To produce a brown to black color on brass, dissolve 1 
pound of plastic carbonate of copper in 2 gallons of strong 
ammonia. Boil the brasswork in a strong solution of potash, 
rinse well and dip in the copper solution which should be heated 
to about 160 degrees Fahr. When the required tint is procured 
rinse and dry off in warm sawdust, then lacquer. 

Bright Dipping Acid 

Sulphuric acid 2 gallons 

Nitric acid 1 pint 

Muriatic acid 1 pint 

Water 1 pint 

Nitre 12 pounds 

Fumeless Dipping Acid 

Sulphuric acid 10 pounds 

Saltpetre 2 pounds 

Water , 5 pounds 



Foundry Mixtures 127 



Pickle For Removing Sand from Brass Castings 

Hydrofluoric acid 1 part 

Water 10 parts 

10 to 15 minutes immersion is sufficient. 

Gold Lacquer 

Shellac 1 ounce 

Gum benzine Y2 ounce 

Came wood % ounce 

(Or Turmeric 1 ounce, Saffron J^ ounce) 

Alcohol 1 pint 

Digest for a week, shaking frequently, decant and filter for use. 

Silver Lacquer 

Bleached shellac 1 ounce 

Gum Juniper Yl ounce 

Spirits of wine 1 pint 

Green Lacquer for Bronze 

Silver lacquer 1 pint 

Turmeric 4 drachms 

Gamboge 1 drachm 

Chemical Bronze 

Vinegar 1 pint 

Crocus of suppliment J4 ounce 

Blue stone % ounce 

Marine brass mixtures. — Shipbuilding is perhaps the most 
important of all the industries creating a demand for alloys. 
Only the best goods will answer for ocean-going steamers and 
some typical mixtures for (a) bearings, (b) propeller wheels 
and (c) other castings used about ships will be considered. In 
speaking of ocean steamers there is a big choice between the 
common tramp and the naval cruiser. A rough classification of 
ocean steamers would divide them into three groups viz. : Ad- 
miralty ships, mail steamers and cargo boats. As to the first, 
everything put into them is of the best and the alloys used 'by 
the various naval departments may be gleaned from books on 
standard metals as Thurston's "Materials of Engineering." 
Obviously the information most sought for relates to steamers 
carrying passengers and cargo — merchantmen. 

Taking the questions in order: (a) includes all moving parts 
of the ship's machinery. To explain, a ship's propeller is gen- 
erally keyed on to a shaft, which passes through the stern tube 
and hangs over the aperture between the stern and the rudder. 



128 Practical Alloying 



In some cases an outer bearing is provided on the rudder 
brace. 

Gun metal liners are either shrunk or cast on to this tail- 
shaft, which revolves in the tunnel bearings, and projects 
through the ship into the sea. Mixtures for shaft liners, tunnel 
and aperture bearings and the stern brushes are given in Tabled. 

Lead figures in these mixtures because it helps to counter- 
act the corrosive action induced by brass and iron in contact in 
a moist atmosphere or under water. 

As a rule, the stern tube is lined with lignum vitae strips 
or babbitt lining, and the tunnel bearings are generally cast 
steel, babbitt lined. A cheap babbitt is best for these parts as 
they are continually under water. A good mixture is lead, 80 

TABLE A 











Yellow 




Copper, 


Tin, 


Zinc, 


Lead, 


Brass, 




per cent 


per cent 


per cent 


per cent 


per cent 




74 


12 








14 


Liners, to shrink on shaft 


60 


6 


— . 


3 


30 


Liners, to be cast on shaft 


81 


10 


— 


8 


— 


Bearings, for aperture bushes 


80 


6 


8 


6 


— 


For tunnel bearings 


66 


6 


— 


4 


24 


Glands and bushes for stern tubes 


83 


10 


7 


— 


— 


Piston rings, springs, etc. 


64 


4 


— 


1 


8 


Steam metal 


8 


6 


— 


2 


44 


Bushes, common castings, etc. 


100 


12J4 


— 


ny 2 


— 


Bearings 


71 


7 


— 


4 


18 


Valves, cocks, etc. 


14 


1 


1 


— 


— 


Bolts, studs 


84 


11 


— 


— 


4 


Hydraulic connections 


84 


10 


4 


2 


— 


Pinions and slides 


88 


10 


1 


1 


— 


Pumps and plungers 



per cent, antimony, 16 per cent, tin, 4 per cent, but a better 
quality, suitable for almost any part of a ship's machinery, is 
composed of lead, 44, antimony, 12, tin, 44. 

Coming now to (b) we will consider propeller wheels, 
Manganese bronze is undoubtedly the finest metal for ship's 
propellers. It is eminently suited for propeller wheels with 
portable blades, and the modern practice is to have the boss, or 
hub made of cast steel and the blades of some high tension alloy 
like aluminum brass, delta metal or manganese bronze. 



Foundry Mixtures 




129 


The analyses of two manganese bronze 
herewith : 


mixtures are 


given 


Per cent 
Zinc 42. 


Per cent 

60.0 

38.0 

0.5 

T.5 





















For solid propellers, that is, where the boss and blades 
are one casting, the best alloy, from a foundry standpoint, is 
the ordnance gun metal, copper 90, tin 10. This alloy is neu- 
tral to the iron or steel of the hull and corrosion is therefore 
slight. 

In making the high-tension alloys previously mentioned, 
which are all in reality copper-zinc alloys with aluminum, iron 
or manganese additions, up to about 2 per cent, it is best to fix 
a standard, say 60 and 40, copper and zinc respectively, and add 
the strengthening elements in some intermediary form as, 
aluminized-zinc, ferro-zinc or cupro-manganese. The shrinkage 
of these alloys is great and with castings showing heavy sec- 
tions, feeding heads are advisable. 

TABLE B 

Anti- 
Lead, Zinc, Tin, mony, Copper, 
per cent per cent per cent per cent per cent 

80 — 12 8. — Metallic packing 

17 — 76 3. 3 Babbitt linings 

4.5 75 18 2.5 — Anti-friction castings, liners, etc. 

— 76 18 — 6 Bearings 

12 — 80 — 8 Plastic metal for pasting 

38 — 42 17 3 Metallic packing for shavings 

12 — 70 12 6 Hard metallic packing 

Lastly, we have (c), formulas for other castings used about 
ships. We shall begin on the bridge and work gradually down 
to the lower decks. On the bridge we have the telegraph gear, 
the bell and the binnacle. The inside parts of the telegraph are 
of most importance ; the cams and pinions require a strong gun 
metal of good wearing quality, copper 88, tin 9, zinc 3, or copper 
88, tin 6, zinc 6. An excellent composition for telegraph and 
ship's bells is composed of copper 81, tin 17, zinc 2. On deck 
the fittings are mostly yellow brass. Copper 63 and zinc 37, 
with lead up to 3 per cent. 

Rails, stanchions and port lights should be of good naval 



130 Practical Alloying 



brass, copper 62, zinc 37 and tin 1, or Tobin bronze, copper 58, 
zinc 40, tin 1 and lead 1. In the saloon and cabins German silver 
is economical and effective for brackets, lamps, etc. A good 
composition which withstands the action of sea air well is made up 
of copper 56, zinc 24, nickel 18, lead 2. A cheaper quality, copper 
54, zinc 30, nickel 16. A substitute alloy is copper 3, zinc 12, 
aluminum 84, phosphor-tin, 1. 

In the engine room all sorts of alloys are required for 
pumps, condensers, dynamos, and auxiliary engines. 

Plastic metal and anti- friction metal for linings should also 
find a place with the engine room stores. Some useful mix- 
tures are given in Table B. 

Nickel bronze. — A strong non-corrosive bronze suitable for 
ship's work, for ornamental castings or stampings, which has 
recently been patented, is made as follows : Make a prelim- 
inary alloy of iron 2 parts, copper 2 parts, zinc 1 part, and 
nickel 1 part. This is added to a "high-brass" alloy consisting 
of copper 54 parts, zinc 40 parts. 

Shipbuilders' alloys. — A number of special shipbuilders' 
alloys are given herewith : 

Manganese Bronze for Propellers, Bolts, Etc. 

Per cent 

Copper 58 

Zinc 38 

Aluminum : 1 

Manganese-copper 3 

Manganese Bearing Bronze 

Per cent 

Copper 75 

Tin 10 

Zinc 4 

Manganese-copper 11 

Phosphor Bronze for Pinions, Brackets, Eccentrics, Etc. 

Per cent 

Copper 86 

Tin 7 

Phosphor-copper 7 

Hard Phosphor Bronze for Piston Rings 

Per cent 

Copper 80 

Tin 12 

Phosphor-copper 8 



Foundry Mixtures 131 



Phosphor Bronze for Bearings 

Per cent 

Copper 79 75 

Tin ! 9 5 

Lead 8 18 

Phosphor-copper 4 3 

Nickel Alloys, White, Non-Corrosive, Strong and Free From 

Pinholes 

Per cent 

Copper 62 57 50 

Zinc 20 20 35 

Nickel 17.5 20 15 

Aluminum 0.5 3 0.25 



Delta Metal 

Per cent 

Copper 50 

Manganese-copper 5 

Phosphor-copper 1 

Zinc 43 

Lead 1 

Delta metal. — According to the Delta Metal Co., one of the 
special qualities of Delta metal which renders it of the greatest 
value for engineering purposes, lies in the fact that its strength 
is but little reduced by an elevation of the temperature. With 
steam at high pressures it is absolutely necessary that the en- 
gine parts and fittings exposed to the heat should be of a com- 
position that renders them perfectly safe, even at such pressures 
as 40 atmospheres (about 600 pounds per square inch) and 
higher. At a pressure of 40 atmospheres the temperature is over 
480 degrees Fahr., and, as will be seen by the following tests 
made by Professor W. C. Unwin, the cast Delta metal had at 
506 degrees Fahr. lost only about \7 l / 2 per cent of its strength, 
while at 500 degrees Fahr., brass had lost over 38 per cent, 



Note: — German silver alloys require the very best metals and great care in 
their manufacture. Melt the copper and nickel together, add the aluminum and 
finish with the zinc. 



132 



Practical Alloying 



phosphor bronze about 31 per cent, and gun metal about 33 
per cent: 

Breaking Strain, Tons per Square Inch 



Temperature, degrees 


Delta metal, 




Phosphor- 


Gun 


k-\ Fahrenheit, 


i m cast 


Brass 


bronze 


metal 


Atmospheric 


23.89 


12.45 


~ 16.06 


■*■" — ■—— - — — — ~" 


210 








ll!66 


270 






14!l6 




310 


23! 36 








350 




11.83 


12!26 




380 








12! 26 


406 








11.06 


410 


22!48 








430 






12!ii 




440 








12.30 


450 




lb'.ko 






500 




7.69 


ii! io 


Y. 84 


506 


19 ! 68 








550 




7! 68 






590 


i6!66 








600 






8!l7 


5^22 


615 








4.82 


635 


12.70 








645 




3^23 







Alloy for bells. — Special alloy for ship's bells: copper 90 
parts, tin 10 parts, aluminum 2 parts. This is equal to cast 
steel in strength. 

Plastic metal. — Richards' plastic metal for pasting: Tin 
70 parts, antimony 15 parts, lead 10j^ parts, copper A 1 /* parts. 

Anti-rust metal. — Bailey's anti-rust gun metal: Copper 
16 parts, tin 2y 2 parts, zinc 1 part. 

Fittings for ships. — Yellow bronze for ship's fittings, 
stanchions, propellers, etc. (Patented) : Copper 60 to 80 
parts, zinc 20 to 40 parts, silicon x / 2 to 4 parts, tin 1 to 2 parts. 
This alloy may be forged or rolled hot. 

Armor plate. — Armor plate, bronze, (Patent Alloy) : Cop- 
per 85 parts, tin 4 parts, iron 6 parts, common salt 5 parts. 

Damascus metal. — Damascus metal for bearings : Copper 
76.46 per cent, tin 10.52 per cent, lead 12.56 per cent. 

Aluminum alloy for automobile castings. — Aluminum 92 
parts, zinc 6 parts and phosphor-copper 2 parts. 

White brass, called "lumen bronze," for axle bearings. — 
Zinc 86 parts, copper 10 parts, aluminum 4 parts. 

Plastic Bronze for locomotive bearings. — Copper 65 to 70 
per cent, lead 23 to 30 per cent, and tin 5 to 7 per cent. 



X 



WHITE METALS 



THE copper alloys bulk so largely in the manufacturing 
world that it is hard to get away from them. Taking 
the melting temperature of alloys as a means of divi- 
sion we have now to consider the more fusible, but none 
the less serviceable alloys, generally classed as white metals. 
Whereas most of the structural alloys, having a copper basis, 
melt in the neighborhood of 1,000 degrees Cent., the white 
metals and alloys require on an average less than one-half that 
temperature for their fusion. Outside of the ornamental white 
alloys — German silver, mock platinum, aluminum silver, and 
the like — and the white anti-friction alloys, there remains an 
important series of white colored metals having special casting 
qualities and high mechanical values. Such alloys as type metal, 
brittania metal, fusible metal, and solder do not belong 
properly to the general foundry practice. The best castings in 
these easily crystallized metals are obtained from chills, but 
owing to their fluidity, giving sharp impressions, and the ex- 
pansion due to the presence of antimony or bismuth, they are 
eminently suited for mixing into pattern metals for sand mold- 
ing as well. 

The advantages of metal patterns as against wooden models 
are so great that their use is warranted for comparatively small 
lots of castings. Cast iron as a pattern metal is open to objec- 
tion because of its brittle nature and its tendency to rust; never- 
theless it may be freely used provided thin sections are avoided. 

For small solid patterns (a) zinc-tin and (b) lead-anti- 
mony mixtures are favored. Usual proportions run (a) zinc 



134 Practical Alloying 



30 to 50 parts, tin 50 to 70 parts; (b) lead 78 to 87 parts, anti- 
mony 13 to 22 parts. 

Solders, or lead-tin alloys are largely used for mounted 
pieces on molding machines ; a good mixture in this class is lead 
50 parts, tin 50 parts. These metals have the advantage of 
being cheap, but if the initial expense of getting up patterns for 
continuous use is not grudged, some of the tin-antimony alloys, 
or better still, the hardened aluminum alloys, will give better 
results as regards stiffness, wear, and conformity to design, be- 
sides being free from objection on the scores of shrinkage and 
clogging of the sand. 

Properties for good pattern metals. — The properties neces- 
sary for good pattern metals are fluidity, low contraction, 
rigidity and strength. For ornamental castings or chased pat- 
terns, a fluid alloy having the important property of expanding 

TABLE XXII 

Pattern Metals 





Tin, 


Zinc, 


Antimony, 


Lead, 


Copper, 


Bismuth, 


Aluminum, 




per cent 


per cent 


per cent 


per cent 


per cent 


■per cent 


per cent 


No. 1 


45 


45 





10 











No. 2 


17.5 


— 


— 


75 


— 


7.5 


— 


No. 3 


— 


90 


5 


— 


— 


— 


5 


No. 4 


3 


85 


— 


— 


10 


— 


2 


No. 5 


— 


90 


— 


— 


4 


— 


6 


No. 6 


80 


— 


20 


— 


— 


— 


— 


No. 7 


65 


30 


— 


— 


— 


5 


— 


No. 8 


16 


12 


12 


60 


— 


— 


— 


No. 9 


8 


87 


5 


— 


— 


— 


— 



on cooling would give the best results ; Nos. 2, 3, 6, 7 and 8 
would answer; No. 6 is a somewhat expensive metal but it is 
well suited for high class standard patterns; No. 1 will answer 
for castings requiring a certain malleability; No. 5 will stand a 
great deal of knocking about, as in rapping a pattern out of the 
mold; No. 4 is a splendid casting alloy but the contraction 
must be taken into consideration in making duplicates. The 
proportions in the above table need not be adhered to so strictly 
as would be the case with alloys required to undergo physical 
tests. Many modifications may be suggested by experience and 
the different requirements of the castings or patterns produced. 



White Metals 135 



Aluminum as a patient metal. — Aluminum has had a great 
vogue, recently as a pattern metal and it has much to recom- 
mend it. Very serviceable, accurate and conveniently handled 
patterns and match-plates, which are easily finished, result from 
the light aluminum alloys generally. Zinc-aluminum is a favorite 
combination nowadays because of the cheapness and strength of 
the product. An alloy of aluminum 75 parts and zinc 25 parts 
shows tenacity equal to 35,000 pounds per square inch and the 
cost pro-rata is much below the ordinary brass or white metal 
mixtures. Alloys of aluminum and tin are somewhat brittle and 
unstable, but the introduction of tin in aluminum-zinc alloys re- 
duces the shrinkage and increases the resistance to corrosion. 

Copper up to 10 per cent makes a convenient hardening 
agent for aluminum, but owing to the known tendency of the 
alloy to segregate on cooling, it is not advisable to introduce 

TABLE XXIII 

Light Aluminum Alloys 











Phos- 






Man- 




Aluminum, 


Zinc, 


Copper, 


phorus, 


Tin, 


Antimony, 


ganese, 




per cent 


per cent 


per cent 


per cent 


per cent 


per cent 


per cent 


No. 1 


90 


8 


1 








1 





No. 2 


96 


— 


2.5 


— 


— 


1.5 


— 


No. 3 


90 


2.5 


— 


— 


— 


— 


7.6 


No. 4 


84 


12 


4 


— 


— 


— 


— 


No. 5 


84 


12 


2.75 


1.25 


— 


— 


— 


No. 6 


80 


15 


— 


— 


— 


— 


5 


No. 7 


77 


17 


6 


— 


— 


— 


— 


No. 8 


75 


23 


2 


— 


— 


— 


— 


No. 


75 


23 


— 


2 


— 


— 


— 


No. 10 


72 


25 


2 


1 


— 


— 


— 


No. 11 


*67 


33 


— 


— 


— 


— 


— 



copper unless in conjunction with some other metal, as zinc, 
antimony, nickel, or tin. Some very useful alloys in this class 
are obtained by adding from 3 to 10 per cent standard German 
silver (melted) to the aluminum in the crucible. The 3 per cent 
alloy, first described by Dr. Richards, contains approximately }£ 
per cent each of nickel and zinc and 2 per cent copper. It gives 
a tensile strength in castings of 22,000 pounds, per square inch, 
with 3 to 5 per cent elongation, and has a fine white color. 

*'The cheapest of all the light aluminum alloys, sometimes called the Sibley 
casting alloy. Specific gravity, 3.8. Tenacity 24,000 pounds in sand castings, 
close-grained but brittle like cast iron. 



136 Practical Alloying 



Strong, light metals are in constant demand and other 
hardeners are being increasingly employed in the production of 
aluminum alloys and castings. Tungsten, chromium, titanium, 
silver, magnesium, and manganese have been used with good 
effects, but the alloys derived from any one of these metals and 
aluminum are all in the way of being specialties. For the most 
part such elements are either so expensive or so refractory as 
to be outside the range of practical foundry operations. The 
new alloy, "Meteorite" = Al + P, is easily produced by pul- 
verizing the requisite quantity (4 to 6 per cent) of phosphor- 
copper and adding it to the molten aluminum. Similarly, man- 
ganese may be conveniently introduced in aluminum-copper 
alloys by using the commercial copper-manganese (30 per cent 
manganese). 

Aluminum solders. — The soldering of aluminum and its 
alloys still presents some difficulty. Hiorns recommends that 
a deposit of copper be made upon the surfaces to be united 
prior to tinning and joining them together. Dr. Richards advo- 
cates the alloy invented by his father which contains aluminum 
1 part, phosphor-tin 1 part, zinc 11 parts and tin 29 parts. 
Numerous patent aluminum solders and fluxes are on the market, 
but it must be acknowledged that cleanliness and the prevention 
of oxidation by some such protective coating as that recom- 
mended by Hiorns, or by the intervention of some reagent at 
the critical temperature, does more to insure a satisfactory joint 
than any supposed virtue in the solder applied. Good results 
have been obtained with ordinary "fine" solder, and bad results 
may be had with any of the patent solders. It is a question of 
mechanical skill and deftness. 

White brass. — A large number of white alloys of different 
grades as to color and hardness are used for casting small busts, 
figures, and ornaments in chills and in sand molds. These 
alloys are principally used in the manufacture of cheap art 
bronzes and novelties which are lacquered. The workers em- 
ployed in casting statuettes in chills acquire great dexterity in 
handling the latter. As soon as the cast is made and the de- 
sired thickness of metal is set (sometimes a mere skin of 
metal), they up-end the mold and drain out the liquid alloy 



White Metals 137 



remaining in the center. This leaves a thin, hollow casting with 
the outline of the bust, figure or design in perfectly regular 
proportions. 

Sorel's alloys containing iron are also adapted for casting by 
this method. For producing zinc-copper alloys containing iron, 
two good plans may be followed: First, melt equal quantities 
of zinc and ferro-zinc together and add from 1 to 10 per cent 
of molten copper; or, second, melt 15 to 20 per cent Delta metal 
and make up by adding plain zinc. Most of the white brasses 
comprised in the range of copper 20 to 45, and zinc 45 to 80, 
are appreciably improved by a further alloy of aluminum, 2 to 
5 per cent. The metal exhibits a higher degree of homogeneity 
and it is more durable and less liable to corrosion. Some 
typical white brass mixtures are given in Table XXIV. 

TABLE XXIV 

White Brass Mixtures 





Zinc, 
per cent 


Copper, 
per cent 


Tin, 
per cent 


Aluminum, 
per^ cent 


Lead, 
per cent 


No. 1 


68 


33 
43 
36 
24 
20 

8 

3.5 
10 

4 

6 
57 
40 


6 

6 

3 
1 

16 
20 
15 
5 


2 
2 

1 

5 




No. 2 . 


57 




No. 3 


56 




No. 4 


68 




No. 5 


80 




No. 6 


91 


1 


No. 7 

No. 8 


90 

88 


3.5 


No. 9 


80 





No. 10 


74 




No. 11 


28 




No. 12 


50 











Nos. 1 and 5 are hard, but easily worked ; Nos. 2, 8, and 12 
are somewhat malleable and can be pressed; No. 11 makes a 
good white brazing solder ; Nos. 3, 4, 6 and 8 are excellent alloys 
for chill castings ; Nos. 9 and 10 are well suited for patterns 
provided the usual allowance is made for shrinkage; No. 7 is a 
cheap mixture for ornamental castings. 

A metal having a lustre equal to the best German silver 
but without nickel consists of copper 50 parts, manganese- 
copper (30 per cent manganese) 40 parts, zinc 14 parts and alu- 
minum 2 parts. 



138 



Practical Alloying 



TABLE XXV 

Special Mixtures 

Tin Antimony Lead Copper Bismuth 

No. 1. Plastic metal 70 15 10.5 4.25 .25 

No. 2. Plastic metal 80 — 12 8 .5 

No. 1. Metallic packing 42 17 38 3 — 

No. 2. Metallic packing 36 8 56 — — 

Tin Nickel Platinum 

No. 1. Bell metal 19 80 1 

No. 2. Bell metal 17 82 1 

Ferro- 
Copper Zinc Nickel manganese 

No. 1. White bronze 68 21 9 — 

No. 2. White bronze 40 — — 60 

Copper Zinc Iron 

White brass 9 89 2 

Manganese- 
Aluminum Zinc copper 
Special pattern metal 90 3 7 

Art metal. — Art metal for casting small figures, plaques, etc. : 
Zinc 90 parts, aluminum 5 parts, antimony 5 parts. This alloy 
is also an excellent solder for aluminum, fluxed with sal- 
ammoniac. Another similar mixture consists of zinc 100 parts, 
with rosin 2 parts, nickel 1 part. This may be used for hard 
soldering aluminum as well as for art castings. 



XI 



SOLDERS, NOVELTY METALS, ETC. 

BESIDES the alloys in everyday use for castings and those 
for manufacturing by rolling and other mechanical proc- 
esses, many metals are mixed and prepared for other im- 
portant purposes, as solders, tempering baths, plastic 
metals, fusible metals, shot, dental stopping, anodes for electro- 
plating, metallic shavings and granulates for steam packing and 
brazing. 

Soldering is the process of uniting two metallic faces by 
means of a fusible metallic cement. The solders are classed as 
soft or hard, according to the temperature at which they melt. 
Soft solders fuse at comparatively low heats; hard solders fuse 
only at a red heat. In every case the solder must be more 
fusible than the bodies to be soldered. As a rule the solder 
approximates in color, composition and properties to that of 
the metal to be soldered. Sometimes two pieces of the same 

TABLE XXVI 

Soft Solders 



Parts 
Tin Lead 



Melts at 
degrees 
Fahr. 



Suitable for baths for 
tempering 



Remarks 



H 



25 
10 
5 
3 
2 



X 



558 


Saws and Springs 




541 


Watch springs 




511 


Hatchets and planes 


Very coarse 


482 


Chisels and Knives 


Common solder 


441 


Razors 


Plumbers' sealed solder 


412 


Lancets 


Zinc solder 


370 




Tinsmith's solder 


334 




Lowest melting point of series 


340 




Fine solder adapted for brass, 
steel, etc. 


356 




Fine, hard, tenacious metal 


365 
378 
381 




Common pewter 










Tinning metal for copper 



140 Practical Alloying 



metal are soldered by heating the edges by means of a blow- 
pipe and kneading them into one. This is termed autogenous 
soldering, but only those metals that assume a pasty condition 
before melting, like lead or aluminum, are amenable to this proc- 
ess. Soft solders are graded as fine, medium or common, accord- 
ing to the content of tin. The ordinary soft solders contain only 
tin and lead, the proportions being varied to suit the work. Table 
XXVI gives some of the best examples. 

Soft solders for delicate ornamental pieces require to be 
more readily fused and more fluid than the alloys given in Table 
XXVII. Pewterers must employ solders that melt below 300 
degrees Fahr., hence we find alloys for their work contain bis- 
muth, cadmium or arsenic in addition. 

Pewter. — Pewter is a tin and lead alloy hardened with 
small additions of antimony and copper. The best qualities of 

TABLE XXVII 

Pewter, Britannia Metal and Fusible Solder Mixtures 

Tin Antimony Copper Bismuth Lead 



100 


8 


2 


2 




Plate pewter 


100 


17 








Best pewter 


75 to 94 


5 to 25 


1 to 9 


1 to 3 




Britannia metal 


59 






12 


29 


Fusible solder 


20 






50 


30 


Melts at 197° Fahr. 


30 






20 


50 


Melts at 212° Fahr. 


1 






1 


1 


Melts 284° Fahr., very fluid 



pewter are akin to Britannia metal, which is a tableware alloy 
with some resemblance to silver. 

The examples in Table XXVII are given as typical alloys 
in each class. The wide range of proportions in britannia metal 
allows considerable latitude in working the metal by rolling, ham- 
mering, stamping, spinning or casting in chills. 

The fusible metals become still more fusible when additions 
of cadmium or mercury are made. Thus, Wood's alloy con- 
tains 5 parts bismuth, 2 parts tin, 2 parts cadmium and 4 parts 
lead, and fuses at 158 degrees Fahr. Another alloy which melts 
at the same temperature is Lipowitz's. It contains cadmium 
3 parts, tin 4, bismuth 15, lead 8. The alloys are very useful 
for soldering tin or lead in thin sections, and britannia metal; 
also for fine castings, impressions of dies where sharpness is 
required, and for soldering in hot water. 



Solders, Novelty Metals, etc. 



141 



An alloy for fusible teaspoons is composed of bismuth 8 
parts, tin 3, lead 5, mercury 1 to 2. By adding 1-16 its weight 
of mercury to Wood's alloy, a new compound, fusible at the 
temperature of the human body, is obtained. Casts are some- 
times taken of small animals with one of these alloys. The 
animal substances are destroyed by a concentrated solution of 
caustic potash, and the metal remains. 

Dentists' amalgams. — Alloys, or rather amalgams for fill- 
ing teeth, should melt in hot water and set hard at about 70 
degrees Fahr. Dentists' alloys for this purpose usually have 
mercury 74 to 78 parts, cadmium 22 to 26 parts. However, gold 
amalgams are most in favor for this purpose. 

Before we leave the fusible alloys there is a novelty in 
amalgams that deserves notice. It is called Mackenzie's amal- 

TABLE XXVIII 

Gold Solders 



■3 -8 .3 e rs o 
< H N (5 w U 


For 9 carat gold, according to Gee, the composition 
For 14 carat gold, according to Gee, the composition 
For 16 carat gold, according to Gee, the composition 
For 18 carat gold, according to Gee, the composition 


For belt (older, the composition approximates .. .. 25 9 

For easy melting solder the composition approxi- 
mate* .. .. 12 7 3 


For very easy solder the composition approximates. . . . . . 5J4 HJ4 64H 28J4 

For dental articles the composition approximates. .. . 2 .. .. 5 1 1 



gam. This amalgam, which is solid at ordinary temperatures, 
becomes liquid by simple friction. It may be prepared as fol- 
lows: Melt two parts of bismuth and four of lead in separate 
crucibles, then throw the melted metals into two other crucibles 
each containing one part of mercury. When cold these alloys are 
solid, but will melt when rubbed together. 

Hard solders. — Passing now to the hard solders, we come 
to alloys melting in the proximity of 800 degrees Fahr. and up- 
ward, and possessing greater variety in color, texture and me- 
chanical properties. Hard solders are prepared in various 



142 Practical Alloying 



forms. For the precious metals the alloys are cast into strips, 
rolled out thin and cut with hand shears, or pressed into suitable 
pieces, termed "pallions;" but if the surfaces to be joined are 
inaccessible to these pallions, the solder is filed into dust fine 
enough for all requirements. 

Hard solders for gold are composed of gold, silver and cop- 
per in proportions to suit the color, hardness and fusibility of 
the standard alloys, as shown in Table X'XVIII. 

Silver solders. — Silver solders are used for all kinds of 
metals and alloys, steel, brass, silver alloys, gold alloys and Ger- 
man silver alloys. The fine solders contain silver and copper 
only. Medium solders contain zinc as well. Arsenic and tin 
are sometimes added to give greater fusibility, and for German 
silver articles nickel and brass have a place. Zinc is generally 
introduced in the form of brass, but it is important that the 
alloy should be free from lead. 

TABLE XXIX 

Silver Solders 





Silver 


Copper 


Zinc 


Brass 


Tin 




1 


4 


1 








Ordinary hard solder 


2 


2 






i 






3 


3 






i 




Tenacious, ductile 


4 


5 






i 




Soft, for fine metal 


5 


8 


0.5 


i.5 






Medium 


6 


8 


0.25 


1.75 






Easy melting 


7 


6 


2 


1 




6.25 




8 


1 


0.75 




32 


2 


Soft 


9 


32 






4 


1 


Hard 


10 


4 


i 




1 




Common brass silver solder 


11 


1 






Arsenic 0.25 


i 


Very easy solder 


12 


2 






" 0.25 


0.75 




13 


8 


5 








For steel_ 


14 


3 


1 








For cast iron 


15 


2 


3 


i 


Nickel 






16 




35 to 45 


40 to 57 


8 to 12 




For German silver 


17 




38 


50 


12 




For steel 



The solders are generally used in the form either of fine 
spangles, dust, granulates, shavings or pallions, and the com- 
position is varied to match the color and other characteristics 
of the work to be joined. The alloys are all white; Nos. 1 to 
8, Table XXIX, are for fine silverware or ornamental manu- 
factures; Nos. 9 to 11 are for tableware and fine brass articles; 
No. 12 is for filigree work. 

Solders for glass and pottery. — No. 1. — Tin 100, zinc 3; 
cast into thin rods for use ; heat the edges and apply. 



Solders, Novelty Metals, etc. 143 



No. 2. — Amalgam, 70 per cent mercury ; make a soft alloy 
of tin granulate and copper dust with sulphuric acid; add mer- 
cury, wash out the acid when mixed ; when solder is to be used 
heat and knead in an iron mortar and apply when plastic. 

Fusible hard solder for aluminum alloys. — No. 1. — Nine 
parts standard phosphor-bronze (no lead), 11 parts tin, 100 parts 
aluminum. 

No. 2. — Mix 8 parts standard phosphor-bronze (filings), 
2 parts tin and 8 parts borax. 

No. 3. — Alloy copper 3 parts, aluminum 9 parts, zinc 14 
parts and granulate ; use cyanide of potassium for a flux. 

Soft solders for aluminum and alloys. — No. 1. — Zinc 25, 
aluminum 6, tin 69; melt zinc and aluminum together and add 
the tin; flux with Venetian turpentine or tin the work before 
soldering. 

TABLE XXX 

Brass Solders 





Copper 


Zinc 


Tin 


Silver 


Suitable for 


No. 1 


58 


42 








Copper pipes 


No. 2 


57 


43 


— 


— 


Brazing metal flanges 


No. 3 


54 


45 


lto3 


— 


Gun metal 


No. 4 


53 


47 


— 


— 


Light flanges 


No. 5 


50 


50 


— 


— 


Brass solder 


No. 6 


47 


52 


1 


— 


Brass solder, fusible 


No. 7 


72 


18 


4 


— 


Malleable 


No. 8 


46 


50 


4 


— 


Half white, fusible 


No. 9 


58 


28 


— 


14 


White, refractory, for steel 


No. 10 


24 


52 


— 


24 


White, refractory, for copper 


No. 11 


10 


— 


— 


30 


White, fusible 


No. 12 


5 


3 


— 


2 


White, fusible 



No. 2. — If ordinary soft solder is fused with one-half, one- 
fourth or one-eighth of its weight of zinc amalgam a more or 
less hard and fusible solder is obtained, which may be used to 
solder aluminum to itself or to other metals. Zinc amalgam 
as used for electrical machinery is made by melting two ounces 
of zinc in a ladle, then removing from the fire and stirring into 
it five ounces of mercury (previously heated). Stir until cold, 
then powder it and keep in a tightly corked bottle. 

Hard solders for brass and alloys. — By far the most impor- 
tant series of hard solders are those for copper and brass — 
braziers' solders. They go under the trade name of spelter 
solders, so-called because of the high proportions of zinc or 



144 Practical Alloying 



spelter in their composition. To make uniform grades of braz- 
ing solder requires careful melting and mixing of the proper 
quality of metals, and they should be poured at the proper tem- 
perature. As a rule a portion of the zinc is mixed in in the form 
of fine sheet or wire brass. The copper-zinc solders have a 
bright yellow color ; a tendency to gray or blue is a sure indication 
of impurities in the metals, such as tin, iron, lead, antimony or 
phosphorus. Sometimes tin is added to increase the fusibility of 
the solder. It is always advisable to have the composition of the 
solder as near to the strength of the metals to be brazed as prac- 
ticable. Copper, iron, gun metal and all the brass alloys have 
different fusibilities and mechanical properties, so that a much 
stronger joint is made when the solder approaches the qualities 
of the metal treated. 

To insure perfect soldering, or brazing, cleanliness is a first 
essential, and in almost every case the solder and the metal to be 
soldered are covered with a flux to ward off the oxygen of the 
atmosphere and to assist in the union of the metals. 

Brazing solder is nearly always used in the granulated 
form, and its manufacture is effected either by pouring the 
molten alloy from a height, or through a strainer, into water, 
or by casting it into slabs or ingots and pulverizing it as soon 
as set. Some manufacturers have machinery for pulverizing 
the highly heated ingots and the grains pass through screens of 
several gradations. This gives grains of regular size and a 
choice of grades for light or heavy work. The discoloration 
and oxide due to the exposure of the hot metal in the atmos- 
phere is removed by dipping the granules in a weak pickle and 
drying off immediately. But coppersmiths place the cast solder 
before the machine-made article; it seems to stand hammering 
much better, and it takes less borax to flux it, probably because 
the grains are globular, Fig. 14, No. 3, while the pulverized is 
like spangles, Fig. 14, No. 1. 

To see the pouring of a heat of brazing solder is to wit- 
ness one of the most interesting spectacles the brass foundry 
affords. The metal is granulated by being poured from a height 
into a tank of clean water. Owing to the high content of zinc 



... ' V "' , 



•4, 



to 







I ti 



Fig. 14 — Brazing solders 




Fig. IS — Method of granulating 
brazing solder 



Solders,, Novelty Metals, etc. 145 

a glowing incandescence, some blue haze and a great deal of 
philosophers' wool permeates the foundry during this opera- 
tion. You stand gazing at the thin red line as it falls 
hot from the crucible into a water grave — no, 'that is too 
poetical — a barrel of water is the actual fact. You admire the 
courage of the caster perched on some rickety, temporary stag- 
ing, placed on the top of a drying stove or a pile of molding 
boxes, when suddenly the illumination ceases, the heat is poured 
off, and, feeling a choking sensation in the upper regions of 
the chest, you rush for the door and miss the best part, which 
is to see the nice, bright, round grains of metal taken from the 
tank, washed under the tap and dried off ready for use. Fig. 
15 is an attempt to illustrate the pouring, but it would require 
a cinematograph to show the effect of the fine stream of molten 
alloy hitting the water, the rising steam, the whirling smoke, the 
snow-like ZnO, and the pyrotechnic display. The height from 
which the metal is poured and the rate of pouring regulates the 

TABLE XXXI 

NON-OXIDIZABLE BRONZES 













Ph 


osphor- 














Copper 


Zinc 


Ali 


jminum 




tin 


B! 


ismuth 


Nickel 


M 


urcury 


ft 1 


2 


15 




80 




1 












*2 


<£> 2 


2 


12 




85 




— 




— , 


— 




1 


J 


1 


8 




90 




— 




— 


1 







4 


88 


8 




2.5 




1.5 




— 


— 







5 


85 


1 




9 




4 




— 


— 




1 


6 


90 

91.5 


6 




4 




6.7 




0.5 


— 




— 


<2> 7 


1.5 




0.03 


0.07 


8 


40 


20 




— 




14 




0.75 


27 






9 


60 


17.25 




1 




12.5 




0.75 


8.5 







10 


72 


22 




2 




4 




— 


— , 







11 


24 


68 




2 




6 




— 


— 







12 


47 


21 




— 




1 




— 


31 




— 



size of the grains. Twelve feet was the fall in this case. Some- 
times a plumbago strainer or colander is fixed in a frame imme- 
diately over the tank; the metal is poured into this and drops 
through in regular-sized grains. The only objections to this 
process are the skulls left in the strainer and the expense. An- 
other method is to pour the metal upon a cast iron ball barely 
covered with water in a shallow dish. On striking the ball the 

♦Alloys containing mercury, arsenic, antimony or zinc show consider- 
able loss of those elements by remelting, so that care must be taken no: 
to overheat the alloy or remelt it without adding new metal. 



146 



Practical Alloying 



metal scatters into small pieces and falls into the water. But 
the finest and most uniform product of all is obtained by arrang- 
ing a horizontal pipe in connection with a force pump. The 
cock on the pipe is opened so that a jet of water is thrown 
across the tank which is to receive the alloy. Upon this jet of 
water the molten metal is poured. The force of the water may 
be regulated so as to give grains of a determined size, within 
certain limits. Some skill is required in the pouring by all of 
these methods if uniform grains are desired. The metal must 
fall in a regular, thin stream, otherwise on emptying the tank, 
a conglomerate, similar to No. 2, Fig. 14, will result. 

TABLE XXXII 

Miscellaneous Alloys 



Copper 



Nickel 



Silver 



Aluminum 



Tin 



Rozine for jewelry, No. 1 43 

Rozine for jewelry, No. 2 — 

Rozine for castings, No. 3 — 

Rozine for castings, No. 4 1 

Rozine for springs, No. 5 — 

New bell metal 87 

Acid bronze 76 

Cobalt bronze 40 

Heusler's magnetic alloy 85 . 

Brass to expand by equal heat with 

iron (Bolland) 79 

Platinum bronze 42 

Platinum bronze — 

Anti-rust alloy for stop cocks 7 

Anti-friction brasses 5 



32 


25 








40 


10 


30 


20 


3 


— 


87 


10 


3 


— 


96 





— 


6 


94 





— 


— 


2 


11 


Lead 


Antimony 






9 


5 
Cobalt 


— 


10 


— 


50 
Manganese 


10 


— 


0.5 


.6 
Zinc 


8 


— 


— 


15 


— 


6 


Nickel 




Platinum 




31 


22 


5 





100 


— 


0.5 


— 


— 


72 


— 


21 


1 


80 


— 


14 



In no case should the solder be left over night in the water ; 
it should be dried off at once to avoid unnecessary oxidation, 
and for the same reason it should be kept in air-tight tins. 
Any attempt to pour a second heat into the same water would 
result unsatisfactorily. The oxides from the first pouring, 
which gather like a scum on the surface of the water, and the 
heat of the water itself would be fatal to the best results. The 
average composition of brazing solders varies between copper, 
58 to 40 parts, and zinc, 42 to 60 parts, the fusibility of the 
alloy being in proportion to the amount of zinc present, 1,150 
degrees Fahr. being approximately the melting point of No. 5, 
Table XXX. 



Solders, Novelty Metals, etc. 147 



For those who prefer to use mixed metals a convenient mix 
for brass solder is to melt 30 to 40 pounds brass wire or sheet 
and add to this 10 pounds of virgin zinc. Copper tubes are now 
manufactured having from 2 to 3 per cent aluminum alloy. The 
British Admiralty adopted the use of these for steam pipes and 
copper fittings, because of the relatively high tensile strength 
and the advantages offered by increased burdens, or the diminu- 
tion of weight in similar structures. An excellent blow-pipe 
solder for this class of work is M. Mourey's, which contains tin 
6 parts, zinc 3 parts, aluminum 2 parts, copper 1 part, silver 
( optional) 1 part. 

To solder without heat. — Brass filings 2 ounces, steel 
filings 2 ounces, fluoric acid 34 ounce; put the filings in the 
acid, apply the solution to the parts to be soldered. After thor- 
oughly cleaning the parts in contact, dress together. Do not 
keep the fluoric acid in glass bottles, put it in lead or earthen 
vessels. 

Novelty metals. — About the middle of the nineteenth cen- 
tury the introduction, for a set purpose, of the metalloids in 
metallic alloys, constituted a novelty in practical alloying. Later, 
when aluminum became a comparatively cheap product, several 
new series of useful and novel alloys made their appearance, 
and with the advances of electric engineering, the conductivity 
and magnetic power of metals and alloys were put into new 
relations. The latest novelty to be recorded is the commercial 
production of some alloys by electro-deposition. There is still 
ample scope for the invention of new alloys and more scientific 
methods of making and manipulating them, and it is along these 
lines that the best work will yet be done. Some metals in alloys 
suffer from over-popularity such as, aluminum, lead, phosphorus, 
zinc, etc. Aluminum, because of its low specific gravity; lead, 
because of the weight and economy of its use in alloys ; phos- 
phorus, because of the fusibility and over-rated refining influ- 
ence it has on dirty metals, and zinc, because of its cheapness 
and toughening effect in other metals. The abuse of these metals 
is well known to those who handle ready-made alloys for the 
production of castings. 



148 Practical Alloying 



Time was when phosphor bronze was held in high esteem, 
but now, because of the indiscriminate use of phosphorus and 
lead, it has fallen out of line. Aluminum was all the rage for 
a while as a mixer, deoxidizer, strengthener and cure-all in iron, 
steel, copper and alloys, but it was over-exploited in these par- 
ticular lines, and the true, legitimate uses of the metal are only- 
beginning to be found out. Perhaps the art section of modern 
industries is responsible for more of the novelty metals than 
any other branch. 

Metals have always been in use for ornamentation, but the 
artistic influence of alloys in recent times has tuned up the 
general style of decorative metal work, and bright chromatic 
effects are giving place to the solid, old-fashioned, monotonous 
design of the wrought-iron period. With alloys we can have 
lightness, cheapness, elegance, strength and variety of color 
scheme combined in the newest are. 

A new argent an which resembles silver and may be worked 

like German silver contains copper 70 parts, nickel 20 parts, 

zinc, 5.5 parts and cadmium 4.5 parts. Some cheap alloys, 

TABLE XXXIII 

Magnesium Alloys 







Copper 


Nickel 


Magnesium 


Aluminum 


Tin 


Zinc 




No. 1 

No. 2 


1.76 
0.21 


1.16 

0.3 


1.60 
1.58 


95.45 
94.0 


3.15 


0.7 









fusible, white, close-grained and in every way suitable for cast- 
ing objects of art are made as follows : Melt three parts of tin in 
a crucible, heat two parts mercury in a hand ladle and add care- 
fully to the barely molten tin ; pour out into ingots. Add five per 
cent of this tin-mercury alloy to the ordinary aluminum-brass 
mixture — copper 57, zinc 42, aluminum 1. The resulting alloy 
has a beautiful pale pink color when polished, and it may be 
used alone or as a hardening composition in white metals. 

Alloys containing mercury. — Though scientifically of inter- 
est, alloys containing mercury are seldom used in the industries. 
Even when the difficulties of combining a metal, which is liquid 
at ordinary temperatures with the refractory metals are over- 
come, the permanence of the alloy is not easily assured, and in 
remelting, the mercury content will be considerably reduced. 



Solders, Novelty Metals, etc. 149 

One mixture which has the advantages of small shrinkage 
and high luster consists of one part of the hardening to two parts 
of zinc. Approximate analysis showed the finished proportions 
to be: Zinc 81.48, aluminum 0.40, mercury 0.72, tin 1.0, copper 
16.22. Other non-oxidizable metals containing mercury are given 
in Table XXXI. 

These alloys vary in color from white to a deep golden hue ; 
Nos. 1, 2 and 3 are aluminum alloys with the luster of silver 
and considerable hardness and elasticity; Nos. 4, 5, 6 and 7 are 
variations of the ordinary bronze alloys; Nos. 8 and 12 are 
nickel bronze, hard and sonorous ; No. 9 is still white and mal- 
leable. 

New magnesium alloys are coming into use, and the com- 
position of two is shown in Table XXXIII. 

SPECIAL MIXTURES 

Special anti-friction lining metal. — Tin, 53, lead 33, copper, 3, anti- 
mony 11; melts at 295 degrees Fahr. ; specific gravity, 7.23. 

E. Murman's improved Magnesium. — Aluminum 100 parts, magnesium 
1 to 10 parts, zinc 1 to 20 parts ; the zinc overcomes the difficulty of ob- 
taining sound castings and the tenacity is not reduced. 

Gun metal for piston rings and springs. — Copper 83, tin 10, zinc 7; 
very elastic. 

Cheap white alloy for art castings. — Aluminum 78, zinc 12, copper 8, 
tin 2; fine luster. 

Red brass for fine ornamental castings. — Copper 82.5, zinc 16.25, bis- 
muth, 1.25. 

Hard solder for bell metal. — Brass 40, copper 10, tin 15. 

Hard white brass. — Tin 67, antimony 11, copper 22. 

Alloy for scientific instruments, named Zisikon. — Aluminum 80 parts, 
zinc 20 parts. 

Brass, tough alloy, will bend double. — Copper 64, zinc 33, silicon- 
copper 3. 

A new alloy for bearings has been patented by Hans Kreus- 
ler, Wilmersdorf, Germany. It is said to have a very low co- 
efficient of friction and consists of cadmium 45, zinc 45, and anti- 
mony 10. 

Charpy has found the alloy containing 83 per cent tin, 11.5 
per cent copper and 5.5 per cent antimony to possess the greatest 
compressive strength. Locomotive bearings are generally filled 
with metal very close to this composition. 



FLUXES FOR ALLOYS 



FLUXES are the re-agents of the smelter and the proper 
use of fluxes is of the highest importance in the pro- 
duction of metals from the ores. Most fluxes act both 
chemically and physically ; they are acid or basic according 
to the oxygen ratio of flux and gangue. Acid fluxes mostly sili- 
cates, are employed to act upon basic materials and vice versa. 
Alkaline fluxes are chiefly used in refining metals. In the found- 
ry, where only refined metals are used, there is not the same 
scope or necessity for using fluxes. 

Many of the so-called neutral fluxes act simply as pro- 
tective coverings to the surface of the metals in the process of 
melting. Charcoal, coke dust, lamp black and such highly car- 
bonaceous bodies give excellent protection in the reduction of 
brass and gun metal alloys. In charging the crucible the very 
first ingredient should be a handful of charcoal or coke dust; 
then as the metal melts and rises in the crucible, the surface 
of the bath is protected from the oxidizing influence of the 
atmosphere. In this way the true character of the alloy is main- 
tained, whereas by careless treatment, overheating or prolonged 
melting in contact with the fuel and products of combustion, the 
best of metals may be rendered worthless. 

It is worthy of note that metals, which are cast, always 
show their natural defects in the casting, but metals which 
undergo mechanical treatment, as rolling, forging, etc., may have 
similar defects entirely removed or at least remedied by the 
process. 

All the good work that can be put into a casting should 



Fluxes for Alloys 151 



therefore be done before the metal enters the mold. The prep- 
aration of alloys for casting requires greater precautions than 
are necessary in the case of simple metal, and the difficulties in- 
crease with every added component, unless there is chemical 
affinity to assist in the combination. 

Even with the most careful melting the metals are partially 
oxidized and gases are occluded or absorbed. To free the metal 
from these oxide compounds and gases in solution, fluxes capable 
of re-dissolving the oxides and removing the gases are intro- 
duced. In some instances it is also desirable to remove foreign 
metals known to be present in the alloys as impurities. 

To free brass turnings from iron, salt them well, moisten 
thoroughly, and after a few days wash with running water. Of 
course, if old metals are used many more impurities are liable 
to be introduced than with new metals. Scrap brass has always 
some impurity clinging to it, grease, paint, sand, solder, red 
lead, cement, etc., and the effect of these contaminations is to 
deteriorate the physical properties of the metal. 

A suitable flux may to a large extent remove the dross and 
counteract the baneful effects of the impurities, but if uniformity 
is desired in an alloy as a regular product, scrap metals and their 
attendant faults and fluxes should be barred. 

Fluxes for alloys. — Following is a list of the most common 
fluxes for alloys: 

For brass. — Potassium carbonate; this consists of pearl ashes mixed 
with damp sawdust. 

For brass. — Potassium sulphate; this consists of sal-enixum mixed 
with charcoal. 

For brass. — Salt cake ; this consists of crude sodium carbonate 5 
parts, silica (white sand) 15 parts, coal dust (anthracite) 5 parts, bone 
ash 20 parts. Mix, cover the surface of the metal, stirring it in before 
bringing to a heat. 

Gun metals. — Equal parts of crude tartar and nitre burned together. 

Gun metals. — Sodium chloride (common salt) is a useful flux in 
reverberatories ; it forms a fusible compound with antimony and arsenic, 
thus removing these undesirable elements from the alloy. 

Gun metals. — Nitre, 3 parts, argol 2 parts ; recommended by T. D. 
Bottome. 



152 Practical Alloying 

Gun metals. — Silica; great hardness and ductility may be given to 
red brass without having recourse to phosphorus, by mixing in with the 
other metals, two per cent of finely powdered green bottle glass, placing 
it at the bottom of the crucible; if the alloy is for parts of machinery 
and to be tooled add one per cent manganese dioxide (Mn0 2 ). The metal 
is rendered very fluid and close-grained. 

Babbitt metals. — Sal-ammoniac (ammonia chloride) ; this substance 
is decomposed by the metals at comparatively low temperatures, forming 
metallic chlorides and liberating free ammonia. 

Babbitt metals. — Tallow or fat of any description and rosin; these 
substances ignite and liberate gases, which unite with the contained oxy- 
gen, thus acting as reducing agents on the metallic oxides. 

Brazing metals. — An improved flux consists of boric acid and sodium 
carbonate in equal parts; this is used instead of borax; it does not in- 
tumesce like the latter. 

Aluminum alloys. — Benzine, resin, cryolite; fluxes proper are to be 
avoided with aluminum, especially sodium compounds; they injure the 
alloy by dissolving the walls of the crucible and introducing infusible 
silica and iron compounds ; overheating is a prolific cause of trouble with 
the light alloys. 

Nickel alloys. — Plaster of Paris and nitre equal parts to be stirred 
in five minutes before casting. 

German silver. — A special flux for German silver consists of silica 
sand 3 parts, ground marble 5 parts, borax 1 part, salt one-half part; 
mix with an equal quantity of powdered charcoal. 

Britannia Metals. — Stearic acid heated and applied to the mold is a 
preventive for faintness in fine chilled castings in soft alloys. 

Brass sweepings. — Mr. E. S. Sperry speaks highly of plaster of Paris 
(CaS0 4 ) as a flux for reducing brass ashes, skimmings, buffings and 
grindings. Such finely divided particles are generally productive of more 
dross than metal if melted in the ordinary way. This is a cheap and 
thoroughly efficient flux. 

Copper. — The purification of copper has received considerable at- 
tention ; zinc oxide and charcoal added to molten copper are helpful in 
producing sound copper castings. These substances are mixed with 
molasses water to a stiff paste, formed into balls and dried. When the 
copper is just melted one of the balls is dropped on the surface; it 
covers the metal and the zinc in the mass combines with any oxygen 
present. Silicon-copper is the best deoxidizer for cast copper, but it 
comes under metallic fluxes. 

Copper alloys. — The following mixture for improving copper alloys 
was the subject of a patent: Iron peroxide 33 parts, manganese peroxide 
1 part, magnesium carbonate one-half part, alum 18 parts, silica 3^ 
parts, borax 4 parts ; mix and stir well into the metal. 

Zinc alloys. — Sal-ammoniac is the best flux and the method of using 
it is to sprinkle it upon the surface of the metal while it is molten. 

From the foregoing it may readily be believed that there is 
no lack of variety of fluxes for alloys, at the same time it can- 
not be too strongly emphasized that the duty of a flux in found- 
ry practice is to purify the metal without entering into com- 



Fluxes for Alloys 153 



bination with it. Such a flux is not easily obtained and some of 
those here given are open to serious objection because of their 
corrosive action on the linings of ladles and crucibles resulting 
in the loss of metal in forming slag and in some cases adding 
new forms of impurity to the metal treated. 

In the refinery, fluxes are essential to liquify and dissolve 
away refuse matters associated with the metals, and their effect 
as solvents may generally be stated in the terms of an equation, 
but in the foundry, where only finished metals are dealt with, 
oxidation is the one thing to be guarded against. 

In the refinery, fluxes are essential to liquify and dissolve 
metallic additions has become universal. Much of the excel- 
lence of our modern alloys is due to small additions of elements, 
which to some extent form chemical combinations with the mix- 
ture. We have already admitted that the chief use of a flux in 
foundry practice is to remove certain faults introduced with 
scrap metals. Now, it seems that object can be attained, and the 
alloy improved, by the use of some metallic flux ( ?), with greater 
ease and certainty, than by the application of the salts and radi- 
cals previously mentioned. 

Tempering metals. — These tempering metals, as they are 
now called, must be used with judgment. Most of them might 
be called concentrated alloys. They include the following: 

Phosphor-copper, which contains 10 to 20 per cent phosphorus 

Phosphor-tin, " " 5 per cent phosphorus 

Phosphor-aluminum, " " 5 per cent phosphorus 

Manganese-copper, " "30 per cent manganese 

Ferro-manganese, " " 25 to 50 per cent manganese 

Ferro-aluminum, " " 10 per cent aluminum 

Ferro-zinc, " " 5 per cent zinc 

Aluminized-zinc, " " 2 per cent aluminum and phosphorus 

Silicon-copper, " " 15 per cent silicon 

Arsenic lead, " " 2 per cent arsenic 

Antimonial lead, " " 20 per cent antimony 

Magnalium, " " 2 to 10 per cent manganese and 10 per cent aluminum 

Zinc-aluminum " " 3 to 33 per cent zinc 

The use of these specially prepared, and in most cases, con- 
centrated alloys, has advanced very rapidly in recent years. 
Phosphor-copper and phosphor-tin were among the first of the 
new tempering metals to be used for fluxing or to impart special 
properties to alloys. The vigorous purifying effect of these 
phosphides on bronze are well known and appreciated, but the 
most important feature in this, as in most of the newer im- 



154 Practical Alloying 



provements in alloys, lies in the fact that the structure changes, 
pointing to a condensation of the alloy, and giving increased 
density, tenacity and fusibility. 

Phosphorus. — For many years phosphorus was the cure-all 
of the brass founder. It livened up dull metal by dissolving the 
copper oxide, which forms so readily in copper alloys ; it also 
increased the utility of lead in brass and gun metals and it was 
supposed to turn old, inferior metals into castings of just as 
fine appearance and as good practical value as could be obtained 
from new metals. 

On this supposition the mistake was often made of adding 
an excess of phosphorus. It was a fatal mistake. Phosphorus 
is a weakening element in any alloy if it remains in solution. 
For this reason only so much as may be necessary to reduce the 
oxides and remove impurities generally from 0.5 to 1 per cent is 
desirable to flux brass or gun metal, while as a tempering 
agent in bronzes the content of phosphorus should in no case 
exceed 2 per cent. 

Owing to the commercial production of these tempering 
metals in definite proportions it is an easy matter to combine 
the exact quantities of the temper desired. 

Aluminum. — Next to phosphorus, aluminum is the most 
popular flux or tempering metal for casting alloys. For some 
years past it has been quite the rage. But it also has proved a 
dangerous element when it has been used indiscriminately. 

Phosphorus is most beneficial in copper-lead alloys, and 
least active in copper-zinc alloys ; aluminum on the other hand is 
positively harmful in copper-lead mixtures and most effective in 
strengthening copper-zinc alloys. The subject of metallic re- 
actions is one which deserves the fullest investigation and the 
active properties of aluminum in metallic combinations are spe- 
cially interesting. 

I am quite convinced that the writer of the advertisement 
for a metal concern knew something when he penned this : "It 
(Al) operates to increase the chemical affinity between the dif- 
ferent elements of the mixture and tends to determine the cop- 
per or higher colored elements to the surface." That statement 
alone did not carry conviction ; but my own experience and the 



Fluxes for Alloys 155 



knowledge of a process by which a cast iron alloy with cop- 
per and aluminum could be made to produce castings having 
the appearance of brass, led me to the conclusion that aluminum 
could either precipitate the copper or alloy with the copper, and 
because of its low specific gravity and high specific heat this 
copper-aluminum alloy appeared on the surface of the casting. 

The value of aluminum in brass alloys is unquestioned. It 
increases the tenacity of brass by more than one-third and gives 
a closer grain and a higher color. It reducess the corrosive 
power of the atmosphere on brass and it is an economical mixer 
in quantities from 0.5 to 4 per cent. The best method of com- 
bining the aluminum is in the form of aluminized-zinc. 

Manganese. — Manganese is another splendid deoxidizer for 
copper alloys. Metallic manganese is hard to reduce, therefore 
an alloy of copper and manganese is the best medium for intro- 
ducing the temper. Usually about two per cent manganese is 
added to the ordinary alloys. Ferro-manganese, ferro-alumi- 
num, and ferro-zinc are frequently used in the production of 
manganese bronzes and sterro metals. 

Certain metals are known to react upon each other in the 
heat to promote fluidity, as silicon, phosphorus, aluminum, and 
manganese in copper alloys, hence, the special preparations sili- 
con-copper, etc., have come to be regarded as metallic fluxes in 
the brass foundry. 

Arsenic. — The element which approaches nearest to the 
action of a flux is arsenic because it promotes the union of 
metals that would otherwise be difficult to mix. Arsenic bronze, 
now used for railway brasses, is a good example. The compo- 
sitions average : Copper, 80 parts ; tin, 10 parts ; lead, 10 parts ; 
the arsenic added equals 8 parts. Arsenic is also useful in help- 
ing to carry a higher percentage of lead in zinc alloys. 

Fluidity of metals. — The fluidity of metals is variable, and 
as a general rule the fluidity of alloys is greater than that of 
the individual metals. Zinc or copper melted by themselves are 
comparatively sluggish, whereas brass, the alloy, is a very fluid 
metal. Zinc alloyed with antimony is more viscid than plain 
zinc while an alloy of copper and antimony is remarkably fluid. 
Aluminum has better flowing power when barely melted than at 



156 Practical Alloying 



higher temperatures, but immediately when it is alloyed with some 
other metal this characteristic loses force. 

Instances could easily be multiplied showing that small addi- 
tions of metals in alloys, — so small as not to class them as 
alloying metals — have the same purifying effect as have fluxes 
proper upon ores. Such metallic fluxes have generally sufficient 
affinity for oxygen to combine with or reduce the dissolved 
oxides in the molten alloy, and the chemical reaction liberates 
gases, which either raise the temperature by a definite amount 
of sensible heat, or lower the melting temperature of the alloy. 
Homogeneous metals result and in many cases the physical 
properties of the alloys are improved in a degree not otherwise 
obtainable. 

So long as scrap metals are a part of the mixture, and 
there is no other practical way of using them, fluxes, whether 
metallic or neutral, must find a place in foundry practice, to act 
as cleansers or as aids to the closer union of the components. 
Very few of the alloys can be melted without decomposition, 
and no metal is exactly the same physically after it has under- 
gone heat treatment. Fluxes are therefore essential to modify 
the defects of every-day melting practice and of all the fluxes 
in use the metallic preparations are the most convenient, only 
they must be used with moderation and in their proper spheres 
of influence. 

Use of metalloids as fluxes. — The metalloids are best adapt- 
ed for use in conjunction with the following metals and alloys : 

Phosphorus in copper, tin, lead and aluminum. 

Silicon in copper, copper alloys and cast iron. 

Arsenic in lead, anti-friction alloys and copper alloys. 

Manganese is highly beneficial in all copper-zinc alloys, nickel alloys 
and aluminum alloys. 

Phosphor-tin, about 0.5 per cent, added to the white anti-friction 
bronzes, will prevent deterioration of the alloy in the heat. 

Copper castings of high electrical efficiency. — Many experi- 
ments have been made in order to obtain homogeneous cop- 
per castings with a high electrical efficiency. It is highly impor- 
tant that the conductivity shall be retained as near to that of 
pure copper as possible, and the metal that is highest in this 
respect will be most in demand, for such castings as are required 
for electrical machinery. 



Fluxes for Alloys 157 



One of the most successful is gained by using Cowles' silicon, 
aluminum and copper alloy (pulverized) and manganese dioxide 
mixed in equal quantities. To two ounces of this, add an equal 
quantity of a flux composed of borax and nitre equal parts ; this 
is sufficient to refine 100 pounds of copper, and is added five 
minutes before pouring. A high degree of conductivity is claimed 
for this metal. 

The following mixture for improving alloys was also the 
subject of a patent : Iron peroxide 33 parts, manganese peroxide 
1 part, magnesium carbonate Yi part, aluminum 18 parts, silicon 
3 l A parts, sodium-biborate 4 parts. Phosphorus and aluminum 
both act as reducing agents in combination with other metals, 
and they are especially active in lowering the fusion-point of 
metals. 

The addition of a flux is always advantageous. It cleans the 
metal, keeps it more fluid in the ladle, tends to set free occluded 
gases, and avoids blow-holes in the casting. Some of the so- 
called metallic fluxes have additional advantages, as aluminum in 
steel and iron, producing metal of superior ductility, toughness 
and softer skin for machining purposes, and taking away the ten- 
dency to chill at the edges or thinner parts of the castings ; or 
bismuth in anti-friction alloys in reducing friction ; or manganese 
in copper, making it possible to cast this difficult metal satisfac- 
torily. 

Flux for welding copper. — Boracic acid two parts, phosphate 
of soda one part ; mix. Heat the copper pieces in a flame or gas 
jet, where they will not touch charcoal or solid carbon ; strew the 
powder over the surfaces at a red heat, continue heating to weld- 
ing point, then hammer. 

Corrosion of metals. — Metals and mortals have their 
peculiarities and they possess many qualities in common. Both 
can be classified according to their affinities, grouped into families 
according to their characteristics, or ranged in line according to 
color. They have similar attributes, as hardness, conductivity, 
luster, etc., they are equally susceptible to treatment, and they are 
subject to many insidious diseases. Up to the present, however, 
only a few of the metallic diseases have been diagnosed. Metal- 



158 Practical Alloying 



lie pathology — to coin a phrase and continue the analogy — is still 
in the chrysalis stage ; it is a modern study about which only the 
most meager, scrappy information is available. The fact that 
familiar, every-day terms are still employed to denote or describe 
the diseases of metals, as fatigue, rust, corrosion, proves the tra- 
ditional conception of the subject to be uppermost. In engineer- 
ing circles there is no more hackneyed subject than the corrosion 
of metals ; it would be difficult, therefore, for me to say anything 
new thereon. My aim, at present, is to bring under review the 
relative position of the more useful metals and alloys to corro- 
sion ; to consider preventives and to describe some experiences I 
have had with the plague in the practice of my ordinary vocation 
— brass founding. 

Corrosion (Latin, cor — intensive, rosus — to gnaw) may 
briefly be described as the decomposition of metals by the agency 
of galvanic or chemical action. In the nature of things cor- 
rosion is a problem for electricians, but, while it may be necessary 
for me to refer to some general principles, I hope by relying on 
well-known authorities to avoid discussion on electro-technics. 
And here let it be emphasized that corrosion must not be con- 
founded with another very common affection of metals, namely, 
oxidation. Oxide or rust may form on the surface of a metal 
and do it little injury, as, for instance, when zinc is exposed to 
air and moisture a gray film of sub-oxide is formed, which pre- 
serves the metal from further oxidation, or when monumental 
bronzes acquire the desirable patina, or colorations due to the 
production of cuprous-oxide in certain molecular conditions and 
the beauty of contour or ornamentation is enhanced. Corrosion 
acts differently. Most of the useful metals have some affinity for 
oxygen, and are therefore subject to oxidation, but all metals are 
conductors of electricity and they are therefore liable to corro- 
sion under certain well-known conditions. 

Contact theory. — The cause of corrosion is popularly ex- 
plained by the theory of the galvanic current. Two metals in 
contact with the presence of moisture form a galvanic couple, and 
the difference of the force of attraction each metal possesses for 
electricity causes a current which has been called the electromo- 
tive force. Electricity is of two kinds, positive and negative, and it 



Fluxes for Alloys 159 



has been found that whatever metals are brought into contact 
with other, they show, when separated, opposite electrification. 
The following example will show how the two electricities may 
be separated from each other by the differing forces of attraction 
of different metals : Let us assume that negative electricity is 
attracted more strongly by copper and positive electricity more 
strongly by zinc. As long as the two metals do not touch each 
other the force of attraction is not called upon to adt, as the two 
electricities are equally distributed over the plates. As soon as 
the metals touch each other, however, equilibrium between the 
electricities will be disturbed. At the place of contact two dif- 
ferent forces are called into action, viz., the force of attraction 
between the two opposite electricities, and the different forces of 
attraction of the two metals; and electrical equilibrium is only 
possible when the resultants of these two forces are equal to 
each other. That is the contact theory briefly stated. 

Chemical theory. — Let us now consider the chemical 
theory. When Volta, who was the first to observe that com- 
bination of two liquids and a metal produced a galvanic current, 
made his discovery, it was also found that greater quantities of 
electricity are generated by the contact of metals and fluids. 
This is due to the chemical energy of the elements, the liquids 
being decomposed by the electrical current. Numerous experi- 
ments have shown that all metals become negatively electrified 
when in contact with alkaline liquids; but in contact with acids, 
different metals behave differently. In the simplest form of 
galvanic battery where zinc and copper plates are immersed in a 
solution of sulphuric acid, the chemical process is as follows : 
Zinc in the presence of sulphuric acid decomposes water into its 
elements, hydrogen and oxygen. The zinc combines with the 
oxygen to form zinc oxide, which unites with the sulphuric acid 
to form zinc sulphate, while hydrogen gas escapes at the surface 
of the copper plate. Negative electricity is produced at the sur- 
face of the zinc plate and positive electricity at the copper plate, 
the potential of copper being higher than that of zinc. It is 
evident that under different conditions the same metals are some- 
times electro-posijtive and sometimes electro-negative to each 
other, and as Prof. Sylvanus Thomson states, "If a metal tends 



160 Practical Alloying 



to dissolve into a liquid there will be an electro-motive force 
acting from the metal towards the liquid and vice versa." 

Galvanic theory. — The theory of galvanic action, in so far 
as it relates to metals, may be summed up thus : A current of 
electricity may be generated by two different metals in contact, 
by two different metals in the presence of a liquid, or by a com- 
bination of two liquids and a metal. Some metals have the prop- 
erty of being positively electrified in contact with other metals, 
or when submerged in a liquid, while others in similar circum- 
stances are negatively electrified, but the polarity of the metals 
can only be known by experimental electricity or by a com- 
parison of the relative resistances of the elements. The mechan- 
ical effect of this motion of the electricities, or current, is the 
separation of the elements, due to their chemical energy and the 
difference of electrical potential. 

Let us now consider the practical aspect of the subject. 
Metals are popularly supposed to be stable bodies. Alas, they 
perish; they oxidize; they corrode; the unseen, in the form of 
gas or electricity, attacks them, and they crumble into powder. 
The universe is a gigantic laboratory for testing materials. From 
the recesses of her alchemical storehouse Nature can furnish un- 
limited re-agents to precipitate the last of the elements. No 
wonder chemists and philosophers tell us "nothing is permanent 
but change." Attempts have been made to counteract the effects 
of corrosion, in some cases by neutralizing the electrical poten- 
tialities of the metal, and in others by re-establishing electrical 
equilibrium. 

In consequence of the rapid deterioration of iron and steel, 
hydraulic and mining machine parts and sanitary appliances are 
preferably made from some material less liable to corrosion. It 
is unfortunate that iron, the cheapest and most useful and im- 
portant of all the metals, loses more of its vitality from this cause 
than any of its rivals. Alloying is said to retard corrosion. Cast 
iron alloys containing copper and lead have been tried, but with 
indifferent success ; nickel steel stands no better than the ordinary 
kinds. Certain chemical alloys, as Parsons Manganese bronze 
and Dick's Delta metal, are said to be immune, but it has been 
found that while they may show little signs of corrosion them- 



Fluxes for Alloys 161 



selves, they afford no protection to other metals like iron or steel. 
This is proved in the case of ship's propellers. Zinc plates and 
linings are just as necessary to prevent corrosion of the hull and 
aperture when these alloys are used for casting propellers as 
when the common brass or gun metals are employed. 

Since the introduction of the electric light on board ship 
there has been a noticeable increase in the number of broken tail- 
shafts, pitted liners and corroded apertures. The importance of 
securing perfect electrical contact in making connections is of 
more moment on board ship than anywhere else. The loss of a 
tail-shaft or the bursting of a condenser tube from corrosion 
may mean a serious loss of life. It is the general practice to 
interpose some inert, non-corrosive substance between metal and 
liquid bodies to preserve the former from the destructive in- 
fluence of corrosion. Thus it is customary to preserve the hulls 
of ships, or constructural iron work of any kind, by a coat of 
paint, and tinning is a favorite remedy for preserving metals 
liable to corrosion, but these things only afford temporary protec- 
tion. There are so many perplexing causes of corrosion that it 
would be impossible to find a universal remedy. Ships are liable 
to be attacked inside as well as outside. Oxidation of sulphur 
from coal, the presence of metals electro-positive to iron and 
steel, the existence of moist air in the holds, the possibility of a 
leakage of the electric current from the dynamo, and other similar 
agents are ever active. Nickel appears to be less readily corroded 
than most of the other metals. Prof. Ernest Cohen, Amsterdam, 
recommends nickel drawn tubes for condensers, and he specifies 
oxide of copper and nickel as being proof against the corrosive 
action of sea water and atmospheric air. 

An instance came under my notice lately, proving that 
nickel-plated table ware was superior to silver-plating for wear 
and liability to corrosion. A new mail steamer was furnished 
with a fine display of E. P. silverware, but some months afterward 
a greenish, speckled coating began to appear on the surface. The 
articles were ordered to be replated, this time with nickel, 
because it was cheaper, and since then they have been giving 
satisfaction. 



162 Practical Alloying 



Much could be written about the relative merits of the vari- 
ous metals and alloys as anti-corrosive substances. Dr. Richards 
says : "Pure aluminum resists corrosion better than almost any 
of its alloys." The same might be said of every other metal. 
Impurities accelerate the corrosion of metals, and it is worthy of 
mention that the laminations in wrought iron plates, or the 
spongy places in a casting, are more readily corroded than the 
homogeneous metal. But oftentimes the casting is blamed for 
the trouble when some other thing is the cause. Owing to the 
sulphur used in its preparation, the rubber insertion used in 
packing valve faces is a fruitful source of corrosion in 
cast iron steam chests, etc. Pure rubber is costly and the com- 
mercial article is loaded with adulterants, especially sulphur. 
When the corrosion is discovered the engineer whines, "We 
don't get castings like we did 10 or 12 years ago." The fact is 
engineers are getting better castings, but poorer supplies, with 
the usual unsatisfactory results. Corrosion is a disease with 
complications, and the personal equation counts for a great deal 
in the combat. 

The diseases of metals may be summed up into three dis- 
tinct classes, according to the nature of the causes which produce 
them : First, diseases of treatment, embracing metals which 
have been rendered weak by thermal or mechanical treatment; 
second, diseases of composition, arising from the presence of 
bodies foreign to the metal or alloy; third, diseases of decay, 
arising from the action of outside causes, either chemical or 
mechanical, on the metal, and leading to deterioration. 



XIII 



GATES AND RISERS FOR ALLOYS 



THE gating of castings reflects the individuality of the 
tradesman more than any other single operation con- 
nected with the art of molding. Why? — Because the gate 
is the. only part of the mold which is made independently. 
Except in the case of machine-made or repetition molds, no indi- 
cation of the duty or design of the gates necessary to run the 
castings ever appears on the pattern. The molder must think 
this out for himself and as often as he gets a new pattern to 
work from, the problem of gates and risers presents itself. In 
the production of castings the making of the mold is not every- 
thing, the gating is not less important than the ramming, 
the venting or the binding. Every different class of work re- 
quires separate consideration. In ornamental castings the gate 
must not interfere with the design; for light castings it must be 
cut to fill the mold uniformly; for heavy castings it should be 
constructed to avoid wear or scabbing and to feed the parts 
solidifying last. 

Again, the gate which would be ample and successful for a 
casting in cast iron would many times bring disappointment if 
used on a similar casting in gun metal and would certainly fail 
with cast steel. Whatever metal may be used, the fluid charac- 
teristics of the metal and its behavior on solidifying, want careful 
study in order to avoid undue shrinkage, draws, cold shuts, scabs, 
scale, etc. With alloys this is especially true. They are fickle 
compounds, and more sensitive to variations of temperature and 
conditions than the homely cast iron. The primary object of a 
gate is to fill the mold with clean metal and in cutting the gate, 



164 



Practical Alloying 



the molder naturally selects the line of least resistance for the 
flow of the metal, unless some other consideration, as machining, 
or avoiding the use of chaplets, is taken into account. Fig. 16 is 



o^o^o^o^o^o 




Fig. 16 — Improper method of gating 




DU □ u □ u □ 



□ 



D 



Fig. 17 — Proper method of gating 

a simple illustration of how not to gate a casting. Here we have 
a spray of washers with square holes. The gates are so led that 
the metal in passing through the mold, must wear away the sharp 
corners and the castings will contain minute specks of sand, mak- 




Fig. IS— Section of a 4-inch brazing 
metal bend 



ing them unsightly and difficult to polish. Fig. 17 shows the 
remedy for this. Fig. 18 is a section of a 4-inch brazing metal 
bend for distillery coils. These castings are only 5-32 inch 
thick. 



Gates and Risers for Alloys 



165 



They are made from a shell pattern with green sand core. 
The core iron, made of f^-inch square iron, comes in two halves 
as shown at /. No chaplets or nails are used ; the core iron 
is rigid when closed and the legs are long enough to balance the 
core. A pressure of 36 pounds per square inch is applied to the 
castings and the best results follow from the method of gating 





Fig. 19 — Method of gating 

a cover for an electric 

drill 



Fig. 20— Method of gating 

when cover is cast 

in aluminum 



shown. Fig. 19 is another example of a light casting, a cover 
for an electric drill motor. The gate shown is for yellow brass, 
but sometimes these are cast in aluminum, when a different 
method is adopted, as shown in Fig. 20. This illustrates 
the fact that gates should vary with the metals used as well as 




Fig. 21 — Skimming gate to insure clean metal 

with the forms of the castings made. The disposition and dimen- 
sions of gates and risers is not a subject about which one may 
dogmatize or lay down hard and fast rules. Similar castings 
may be successfully run by different gates. Take the blank gear 
wheel, Figs. 24 and 25. Five different gates are shown, any one 



166 



Practical Alloying 



of which may be adopted with success if attention is given to the 
casting temperature (gun metal is meant) and the condition of 
the mold. The question of machining often decides the method 
of pouring. A casting which has to be machined all over is gen- 
erally cast vertically, or with the smallest area at the top. Fig. 
24 fulfills the latter condition better than any of the styles seen 
in Fig. 25, but it is open to objection on account of the gate being 
placed on the most critical part of the casting, that is, where the 
teeth are to be cut. The easiest way to make a mold is not 
always the best for the casting ; much depends on where the im- 
portant parts are located. Usually, particular parts or machined 





GATES 



Fig. 22 — Method of gating 
liners and gun metal rolls 



surfaces are made to form the under side of the casting as the 
top side, in horizontal pouring, is always weakest. Fig. 26 
shows the general practice in marine brass foundries in casting 
valve seats. The mold is made with the flange uppermost and 
when it is finished it is turned over and what was the drag in 
molding becomes the cope in casting. The tiniest" speck on the 
face of this casting would condemn it. Engine brasses supply 
another example of the same practice. Fig. 27 illustrates one 
style of gate and Fig. 28 is an alternative gate used with such 
castings as are molded in three-part flasks. The whole of the 



Gates and Risers for Alloys 



167 



gate, Fig. 28, is cut in the cope, except the small leaders repre- 
sented by dotted lines in Fig. 27. 

Casting brass on iron. — The most troublesome job that falls 
to the lot of the brass founder is to cover a rod of iron, say a 
pump rod or a shaft, with a liner of gun metal, Fig. 29. To cast 
a liner on a shaft is a simple enough matter in itself ; but to 



x y v v 


) *^W$&$X)& 


\v 


// H \VA\ 




XX<XXX><XXX>C 
^xxxxxxxxxxx 


r~ — l 



r 



Fig. 23 — Method of gating a stair 
tread 




Fig. 24 — One way of gating 
a blank gear 




Fig. 25— Four different methods of 
gating a blank gear 



Fig. 26 — Usual method of 
casting valve seats 



obtain it free from blow-holes, cracks or strains is the difficulty 
with which the brass founder must contend. 

Casting brass onto iron or steel is always a difficult matter 
to accomplish satisfactorily. The expansion of the metals is 
different, causing cracks; the affinity of the metals is weak, the 



168 



Practical Alloying 



iron repelling the brass and creating sponginess ; besides it is well 
known that iron, when it is heated, emits a gas, which in the 
'case of shaft liners accumulates inside the mold when it is closed 
and is absorbed by the molten brass when it is poured, producing 
troublesome blow-holes. The remedies for these evils are first, 




Fig. 27— One style of gate 

used for casting engine 

brasses 



Fig. 28— Gate for a casting 
made in a three-part flask 



not to overheat the iron, a very dull red scarcely perceptible in 
the shade being all that is required ; second, to provide sufficient 
risers for carrying off the gases and feeding the casting. Pump 
rods, feed screws, eccentrics, and other small gear, are usually 
lined in vertically cast molds, but with tail shafts running 12 feet 
and upwards in length, and weighing several tons, this method is 
impossible. Horizontal pouring may be quite as successful if the 
precautions already indicated are taken. From Fig. 29 it will 




-BED PLATE 

Fig. 29 — Arrangement of mold for casting brass on iron 

be seen that a bed plate is leveled to receive the shaft which is 
supported by iron stools having V-shaped notches on the top. 
Strips of wood the required thickness of the liners are then tied 
around the circumference to form the patterns and the molds are 
rammed up with the shafts in position, the parting being formed 
at the center. The copes are then removed and the shaft lifted 
out and placed on supports ready for heating. Great care is 
necessary in this part of the work as the shaft is liable to warp 
if it is not properly blocked up. The number of risers strikes the 



Gates and Risers for Alloys 



169 



average molder as being abnormal, but these are exceptional cast- 
ings and if an open, continuous riser could be arranged for, in- 
stead of a series at short intervals, the results would be even 
better. Risers are chiefly used to relieve the pressure on the 
mold, to prevent gas cushions, to collect dirt, to keep open com- 
munication with the mold as a tell-tale during the cast and to 
feed heavy internal sections. 

Risers are never used on large bells because the metal, to 
ring well, should be as dense as possible; this object can only be 



CAST IRON 




SOUC PHOSPHOR BRONZE 
1 




Fig. 30 — Method of casting a pinion with a 
horn gate 

attained by giving the sounding rim all the pressure available. 
To prevent sullage or dirt entering the mold, what is termed a 
plug head is used. A dry sand runner basin is made up on top 
of the mold and a plug made to fit the down-gate by casting a sec- 
tion from the gate pin in plaster of Paris and inserting a hooked 
iron therein before the mixture sets. This plug is fixed in the 
gate, while the head is filled with metal. It is then lifted out by 
using a rod of iron as a lever and the ladle keeps a constant level 
of metal in the head until the mold is filled up. The plug head is 
largely used for statuary and heavy ornamental castings. 

Other forms of gates devised to admit only clean metal to 



170 



Practical Alloying 



the mold are skimming gates, Fig. 21 and core gates, Figs. 31 and 
32. We have seen then, that the gate varies with the style of 
casting and with the nature of the metal. For thin, light yellow 
brass castings as stair treads, Fig. 23, the gates should be shal- 
low and wide, with a heavy down-runner to make it easy to fill 
the mold quickly. Another fine example in this class, but of a 
more ornamental nature, is shown in Fig. 34. This is the re- 
production of a match-plate for a casting made by the National 
Cash Register Co. Such castings require skill in pouring the 



fll 



Fig. 31 — One style of core 
gate 



gate. 





Fig. 3£— Cross-section of mold showing the F'g- 33— Casting a propeller 
, . blade in a vertical 

use of a core gate positkm 

metal; indeed in foundries where much light work is made the 
pouring is done by a class of men called casters. These men are 
expert in filling such molds, and wasters due to irregularities in 
pouring are reduced to a minimum. It may be mentioned here 
that we have intentionally avoided any reference to the fixing of 
gates on machine-made molds. That is a special branch of the 
subject which would be better dealt with by an expert in machine 
molding. Great ingenuity is often displayed in arranging the 
patterns for an odd-side, or for spray work in plate molding or 
machine-molding. The main object is to press as many pieces 
as possible within the area of the flask, in positions that will give 
good, clean castings, with gates which will be economical of metal 
in casting and also of labor in cleaning. 



Gates and Risers for Alloys 171 

Hoiv to gate castings. — A few pointers on gating follow : 

The flow of metal should not meet with any obstruction on 
entering the mold. 

As a rule, the mold should be gated at a heavy part. 

The smallest sprue, which will run the casting satisfactorily, 
is the best for overcoming faults in pouring. 

The drop gate is very useful for thin castings of large area 
as well as for heavy castings with variable thicknesses. 

In some cases a cleaner and sounder casting can be obtained, 
when the metal enters at or near the bottom. 

Round gate pins give the best results generally. 

Spray gates should make a short connection with the leader 
and they should always be deeper and wider there than at the 
mold cavity. 

The pouring basin or head should be so constructed that it 
can be kept full, otherwise the dirt, which collects on the surface 
of the metal, will be washed into the mold and result in a de- 
fective casting. 

Core gates are useful when it is desirable to fill the mold 
with a gentle stream from the interior. 

On intricate castings the gates must be distributed to insure 
that the metal shall reach the vital parts in good condition; at 
the same time care must be taken to avoid scabs from the metals 
impinging upon weak internal parts. 

In gating phosphor bronze castings, molded in green sand, 
make a practice of feeding the heavier parts through the nearest 
lighter section. 

Don't experiment with a new gate if the one regularly in use 
gives satisfaction, unless it is to economize metal or facilitate 
molding. 

Heavy castings call for good judgment to decide upon the 
size and number of gates required. 

Alloys high in zinc, as manganese bronze or Muntz metal, 
should have heavy plug heads for heavy work. The plug head, 
which is simply a dry sand head with a plug fitted in the runner, 
is also used for casting statues made by the cire perdu process. 



172 Practical Alloying 



In making up the head for a large mold the runner basin 
should be central, if possible, so as to give an equal distribution 
of the metal to the gates. Making up the head is a part of the 
work, which is apt to be hurriedly done, since it is the last duty 
in preparing the mold for casting. Carelessness in this part of 
the work will spoil the casting just as readily as bad molding. 
The gates illustrated, are only a few selected for their interest 
to general brass founders. 

Firms adopting a specialty soon find out the most practical 
means of gating the castings they make. For example, screw 
propeller blades for ships are recommended to be cast in man- 
ganese or aluminum bronze. It was found that the horizontal 
method of pouring such castings in gun metal gave unsatisfactory 
results with the alloys mentioned. Now, propeller blades in 
manganese and other bronzes are invariably cast in the vertical 
position, Fig. 33. This is an ideal style of casting for pouring 
on end because it is self-feeding and in cooling out it sets from 
the bottom upwards. Nevertheless, horizontal pouring is neces- 
sary when gun metal is used. The liquidation of the tin in heavy 
masses of gun metal, would produce a casting with brittle edges 
and irregular composition in the thicker parts of the blade if it 
were cast vertically. 

Fig. 35 shows the gate on a church bell; Fig. 22 shows the 
method of gating liners and gun metal rolls; Fig. 30 shows the 
use of the horn gate ; the illustration is a cross-section of a pinion 
wheel for heavy gears and they would probably weigh from 60 
to 100 pounds. Dry sand molds are essential for this class of 
work. The ordinary method of avoiding air holes in such cast- 
ings is to flow a surplus of metal through the mold. It is believed 
that the gases rising from the heated iron are, by this means, 
carried away from the casting. With a sluggish fluid like gun 
metal, this flushing of the mold is good practice, but with a 
highly fluid metal like phosphor bronze it would be positive 
extravagance. For this casting I would recommend a good, old- 
fashioned horn gate; for the larger sizes two gates at opposite 
points, to be poured with two crucibles, with risers distributed on 
the cope at regular intervals, say six inches apart all around the 
circumference. Fig. 30 also shows a cross-section of the rim of a 











»:,:£&.;. 



M**!^ 



Fig. 34 — Match-plate for a brass, cash register 
casting 




"- 



Fig. 35 — Method of gating a church 
bell 



Gates and Risers for Alloys 173 

gear with a horn gate and risers ; 1 shows a cross-section of the 
gear when cast blank and 2 when cast with the teeth in it. 

The cast iron center should be of close-grained iron and it 
would be a decided advantage to have it twice heated before be- 
ing placed in the mold for casting. Perhaps the most import- 
ant consideration in such castings is the temperature. The iron 
should not be raised above a dark cherry hue when first heated. 
At the time of casting, a dark red heat should be sufficient. 

As regards the casting temperature of alloys, we have still 
to depend upon rule-of-thumb. I would not advocate hot metal 
for this job as some do, because the hotter the metal is made, 
the more active it is to form and absorb gases. The blow-holes 
complained of are common to all the conditions of casting copper 
alloys upon iron and it is always possible to minimize them by 
conducting the gases freely from the mold. 



XIV 

ABOUT CRUCIBLES 

THERE is a book entitled, "Crucibles, Their Care and Use," 
published by the Joseph Dixon Crucible Co., Jersey City, 
N. J., which should be in the hands of every crucible 
user and every melter of alloys. The purpose of this 
book is to inform the user of crucibles as to their nature and 
characteristics, and to give him suggestions as to their care and 
handling, which, if followed, will add to their efficiency and 
greatly prolong their usefulness. 

We must concede that the makers should have learned by 
this time about all there is to know of the use and abuse of cru- 
cibles. The graphite crucible is the last word on melting pots. 
For mixing all sorts of alloys it is an ideal vessel; refractory, 
flexible, capable of withstanding sudden changes of temperature 
and strong enough to be handled with freedom, but not with im- 
punity as some people imagine. If you are going to get the 
best out of anything, you must give it your respect. The plum- 
bago crucible is like this, and nearly all of the troubles com- 
plained about are due to the absence of the last named attention. 

In my experience, crucibles are like men, if you treat them 
properly you get a fair return. The average life of the crucible 
depends greatly upon the conditions under which they are 
worked. The crucible, which is used in one of the modern tilt- 
ing furnaces, may give 100 per cent more heats than the one 
used in a pit furnace with a blast connected. A good general 
average of heats for the various metals melted in a natural 
draught coke or coal-fired furnace would be for brass, 40 heats ; 
for gun metal, 35 heats ; for copper, 22 heats ; for German silver, 



About Crucibles 175 



18 heats ; for malleable iron, 16 heats ; for steel, 7 heats and f or 
nickel, 4 heats. 

These figures, however, just as they are beyond the attain- 
ments of some people, would not satisfy the requirements of 
other and more expert melters who are capable of a melting ratio 
far more favorable to the use — and by the same token to the 
maker — of the crucible. 

Causes of premature failure are annealing on the top of the 
furnace, bad fitting tongs, improper charging of the metals, ram- 
ming of the fuel, soaking and rough usage. 

Figs. 36, 37, 38 and 39 amply illustrate the troubles to which 
crucibles are prone. The scalped crucible, Fig. 36, is a sight to 
make the gods weep. The potter's vessel dashed in pieces by 
gross carelessness. Let the manufacturer explain, if he can. 
And he does in this way: "When the crucible comes from the 
kiln it contains less than one-quarter of one per cent combined 
moisture. In this connection it is absolutely impossible to scalp 
it, but the moment it cools off it begins to absorb moisture from 
the air, and once absorbed it requires a temperature of not less 
than 250 degrees Fahr. to dispel this moisture. It is also essen- 
tial that the crucible be kept to this temperature to prevent its 
absorbing the moisture again." 

So simple! And yet many profess to be astonished when 
disaster follows neglect. For the proper annealing of crucibles 
four rules should be observed: 

First — The temperature must go above 250 degrees Fahr. 

Second — This temperature should be reached gradually. 

Third — This temperature must be held long enough to expel 
the moisture in the crucible. Ten hours is given as an approxi- 
mate time for a No. 200 crucible. 

Fourth — The crucible must go in the melting furnace with 
a temperature above 250 degrees Fahr. 

After the crucible has been successfully annealed, some 
melters breath freely and concern themselves no more about it. 
Now, the crux of the question of crucible longevity lies in giving 
proper treatment and care to the pots from the time of delivery 
to the time of doubt, that is, when it reached the condition shown 
in Fig. 37, and deserves honorable mention for long and faithful 



176 Practical Alloying 



service. Alligator cracks is another serious defect, due to hot 
gases and improper annealing. It matters not if you use oil or 
solid fuel, all fuels culminate in gas and the products of combus- 
tion. The moisture in the hot gases condenses on the wall of 
the crucible, an oxidizing condition develops and alligator cracks 
are the result. 

Pin holes, Fig. 38, are a more subtle defect. They develop 
after the crucible has been in use for some time, and it is not so 
easy to apportion the blame for their appearance. The manu- 
facturers admit the possibility of an occasional bad pot, but most 
practical men will appreciate the wide margin which exists be- 
tween the number of heats obtained by a careful and skillful 
melter and one who does not bring the same care and intelligence 
to bear upon his work. Pin holes are probably small fissures 
developed either during the drying or the annealing of a crucible, 
and the personal equation seems to enter largely into the disorder. 

The squeezed crucible, Fig. 39, bears witness to the kind of 
tool in use and the kind of men who use them. 

Two things about crucible economy loom up with im- 
pressive persistence and vigor: First, moisture is the greatest 
enemy to the life of a crucible, and second, prolonged melting 
and intermittent heats are responsible for most of the poor aver- 
ages in ordinary foundry practice. 

It is just as well to remember that the enemy in the form 
of moist, hot gases due to imperfect combustion, say when you 
are holding back the metal to suit the molder, may be getting in 
some deadly work unknown to you, except by a low average of 
heats from the crucible. And you can hardly put a bigger strain 
upon a pot than to leave it out in the open overnight and charge 
it cold into a fresh fire in the morning. 

As regards the shape and capacity of crucibles, the most 
popular shape for alloys is the wide-mouthed Scotch pattern. 
For steel and metals requiring high temperatures, the barrel or 
olive shape is favored. The actual capacity of the different 
styles varies with the nature of the metals melted. Crucibles for 
brass are made in England to hold one pound of molten metal 
per size unit, and a No. 20 pot will hold 20 pounds of metal. 
The Scotch shape is proportioned to hold two pounds per number, 





Fig. 36 — A scalped crucible 



Fig. 37— Crucible showing the cracks 

which begin to form at the top 

when its life is nearly ended 





Fig. 38 — Crucible showing pin-holes Fig. 39 — Crucible squeezed out of 
from which metal has leaked shape by tongs 

Illustrations from "Crucibles, their care and use," published by the Joseph Dixon 
Crucible Co., Jersey City, N. J. 



About Crucibles 177 



and American shapes have capacities up to three pounds of metal 
per size number. As the capacity of a crucible is sometimes 
limited to the amount of light or bulky scrap which it can con- 
tain in unmelted form, the reason for favoring a wide-mouthed 
shape for alloys will be quite obvious. 

The question is often asked "Who makes the best crucibles?" 
The answer to that is contained in the answer to another ques- 
tion, "Who takes the best care of his crucibles ?" 

Some uses for old crucibles. — Plumbago crucibles are an im- 
portant item in brass and steel foundry expenditure, but as the 
expense is a necessary one, it behooves the practical tradesman 
to be careful how he uses them. I can answer for my own 
method as being both safe and economical. Our standard num- 
ber of heats for melting brass in crucibles is 34. I fancy I hear 
a snicker go round at the modesty of the figures. Someone is 
sure to exclaim : "Oh! we can get 40 heats on an average and we 
have had '50 not out' on more than one occasion." I believe 
that, because I too have had the same pleasure. When I say that 
the standard number of heats with us is 34, I mean to imply 
that we look upon that number as the minimum we should get 
with ordinary usage. We melt 17 heats per week from each 
furnace, and every crucible we put in is expected to wear for a 
fortnight ; but under no circumstances do we use one for a longer 
period than 3 weeks. When we have had the use of a crucible 
for a -fortnight continuously, we reckon it has paid for itself, and, 
if at the end of the third week it is still sound, as often happens, 
the chances of its giving out within the next day or two are too 
great to make it worth while risking the loss, danger and annoy- 
ance which always accompanies a burst, either in the furnace, or 
out of it. 

Many furnacemen make a practice of sweating the pots by 
putting them, mouth downwards, . back into the furnace every 
night after the last heat, ostensibly to keep them clean. I find 
they can be kept clean much easier and with less wear, by paying 
attention to the inside wall when skimming the dross off the 
metal, or at the finish of each heat. When the last heat for the 
day has been cast, it is always better to empty the crucible and 
turn it upside down behind the furnace it was taken out of, 



178 Practical Alloying 



leaving the back half of the furnace uncovered. This allows the 
crucible to cool out gradually and avoids much of that cracking 
noise you hear when it is cooled in a draught. 

A new crucible should not require sweating before the 
twelfth or fifteenth heat and about every ninth heat thereafter, 
but much will depend on the nature and condition of the metals 
to be melted. With clean ingot metal it is easier to have clean 
crucibles and increase the average number of meltings. 

The man who gives his pots a nightly sweat gets them thin 
and fragile in a much shorter period than the non-sweater. That 
means his crucibles are more liable to squeeze, split or collapse. 

The other extreme is reached by the lazy villain who never 
sweats the pots at all, but leaves the spare metal to set in their 
bottoms and wonders why so many pots run with the first charge 
in the morning. If, through inadvertence, you should at any 
time have metal set over night in the bottom of a crucible, take 
my advice and dump it out before you recharge it. Put some 
borings or other metal in the bottom before placing the nugget 
back in the crucible ; you can then proceed to melt the metal with 
confidence. 

I have come to the conclusion that much sweating saps the 
life of the pot, just as it would the potter were he amenable to 
the process, and the sweating system is good for neither pots 
nor people. 

The career of a crucible is oftentimes an instructive lesson. 
When it has rendered good service and worn itself out as a melt- 
ing pot it may still be utilized for many purposes undreamt of by 
the makers. One has only to look around one of the jobbing 
foundries to realize this. There you may see the crippled- 
crucible-swap-pot, or the plumbago parting sand dish, and if you 
happen to know in which suburb the manager lives you may 
tell his house by the sable flower pots in the side passage. 
There is no great novelty in any of these adaptations and it re- 
quires no inventive ferment of the average brain to discover 
many similar uses for faithful old crucibles. The genius, being 
differently constituted, intuitively finds an entirely new use for 
any old thing; he cuts and carves it to his liking. Witness that 
original idea for a self-skimming ladle. The recipe is as follows : 
Cut an old crucible in halves longitudinally; when daubing the 



About Crucibles 179 



ladle fix one of the pieces inside near the pouring lip, to form 
a pocket or division. Another good idea is to cut the bowl of one 
of the larger sized pots, say 5 inches from the bottom, invert, and 
place on the fire-bars of the furnace, to be used as a stand for 
the melting pot to sit upon. This arrangement saves fuel and 
has the advantage of keeping the crucible always at the same 
height in the furnace. In the same way old bottoms make handy 
crucible covers for melting steel, or German silver alloys. I do 
not pretend to know all the ways in which worn out crucibles can 
be used ; I have seen them used as annealing pots ; also for burn- 
ing parting sand in; and when the sight of them has become tire- 
some, a last charge of skimmings or washings would be packed 
into one of them and melted over night. In the morning the 
staunch old friend would get his death blow; the button of metal 
would be put on one side, while the remains — well, I shall have 
more to say about the remains further on. 

Economy is a virtue and I want to instil it by showing that 
dilapidated crucibles may be put to some more profitable use 
than the decoration of the foundry dump or truck heap. Even 
if they are beyond any of the uses already mentioned, they 
may be ground and mixed in many ways with obvious advan- 
tage. In some localities hawkers buy up broken crucibles for 
a few cents per hundred weight; and resell them to the facing 
mills. It struck me as peculiar that the material in a graphite 
crucible should realize so little when it was done with for melting 
purposes, especially when it is taken into consideration that the 
heat treatment it receives makes no appreciable difference on 
the incombustible ingredients. When you cut off the glaze from 
the outside of an old crucible there is practically no difference 
in the body of the material; besides if it pays a hawker to collect 
and resell them to the grinders, why should it not be profitable 
for the foundryman to grind them himself? Every foundry of 
any size has a mill and some hair sieves. Let us see what can be 
made of the stuff anyhow! "Pugging" is a trade name for the 
soft fire clay, cement or mortar used for repairing chimneys, fur- 
naces, etc. The best pugging I know of is ground crucibles 
mixed with clay wash. The ordinary sand daubing is vastly im- 



ISO Practical Alloying 



proved by the addition of a shovel full of ground crucibles. Pure 
plumbago facing does not adhere well to the surface of green 
sand molds but mixed with ground crucibles and talc up to 20 
per cent it may be relied upon. Ground crucibles mixed with oil 
makes a splendid substance for stamping branch cores, or for 
getting a bearing by making up the space between core and 
print, or core and core, as the case may be. Steel founders 
use fire clay in some of their facing sand mixtures but ground 
crucibles is a good substitute; it also makes a good mixer for 
core sands, in brass foundries, wherever the ordinary mixtures 
are liable to burn or fuse. Moisture in a crucible before it under- 
goes annealing generally results in its being scalped; but when 
once it has been thoroughly annealed there is not the same risk, 
if a little moisture gets on the outside of it. 

My reason for making this statement will be explained by 
what follows : Many years ago I received my first appointment 
as a foreman brass molder ; it was in Edinburgh, Scotland, and 
there were 14 crucible furnaces in the shop. The first morning 
I was perplexed to see the two furnacemen brushing the outside 
of the crucibles with a black looking slurry, before charging them. 
On the second morning the same maneuvers were gone through 
so I ventured to ask for an explanation. I was informed that this 
had been the practice ever since "Mr. James," came back from 
France,— some 14 months. The mixture consisted of fire clay 
and our old friend ground crucible, half and half, mixed with 
water. A new pot was put in for the first day au naturel; after 
that it got its morning coat of black jack. The result convinced 
me that "Mr. James" was no friend of the crucible manufac- 
turer. His method added at least 30 per cent to the average life 
of a crucible. 

To make a stirrer with black jack, put two strips of 
wood on a face board, as you would in making clay thick- 
nesses. Let them be \y A inches apart and \y 2 inches thick. Pack 
the space with the mixture, which is improved if moistened with 
liquid core gum instead of with water; insert a bar of l^M" 
inch iron, raggled for about 16 inches at one end. Slick-off the 
superfluous mixture, allow it to stiffen, unscrew one of the strips 
of wood and lift the affair into the stove. In the morning you 
have a home-made plumbago stirrer. 



XV 



TESTING ALLOYS 



THE manufacture of testing machinery has been brought 
to such a high state of efficiency, that many firms making 
high class castings for which tests are essential, prefer 
to install one or two machines and perform all tests in 
their own workshops. Messrs. W. & I. Avery's testing machines 
are in use in some of the largest engineering laboratories in the 
world. They have a reputation for being sensitive, accurate and 
of sound construction. 

Fig. 40 is an illustration of an improved, hydraulic, vertical 
testing machine, single lever type, for tensile, compressive and 
transverse tests, capacity up to 150 tons. 

Fig. 41 is a novel impact testing machine which is self- 
registering, indicating the number of foot-pounds of energy 
absorbed by the specimen, which is fractured in one blow. The 
value of testing by impact has been fully demonstrated particu- 
larly when any material is required to withstand shock. An-r 
other feature of impact testing is that the fractures made show 
agreement with the micro-structures, and enable the expert to 
determine the relative contents of the specimen and its previous 
thermal treatment. 

All physical tests are comparative, and it is a mistake to 
rely upon any single test for the capabilities of any material. 
With alloys, the tensile test is too often the only one. Differ- 
ent metals call for different tests and comparisons, and if a 
combination of two or more tests are conducted simultaneously 
on the same metal, a great deal more of its history can be as- 



182 Practical Alloying 



certained, and better work may be done through the application 
of the knowledge thus gained. 

Tests for various metals. — The recognized tests for cast 
iron are the transverse, tensile, compression, impact and shrink- 
age tests. 

For gun metals the principal tests are tensile, torsion and 
impact. 

For high tension bronzes the principal tests are bending, 
tensile, torsion and elasticity. 

For anti-friction metals, the principal tests are compression, 
friction and hardness. 

Whatever the nature of the test, some force is directed 
upon the material, and calcuations based on the amount of 
work done, are made. This does not show the relation of the 
test piece to forces outside of the original test, hence the need 
for combining several tests in one sample of the alloy. All ten- 
sile tests should be accompanied by a statement of elongation 
and the reduction of area. The transverse test is chiefly used 
for cast iron. All friction tests should indicate the method of 
lubrication, if any. 

Notes on test bars. — A few suggestions regarding test bars 
are given below : 

It is usual to make two bars for every test. 

Test pieces of large section give lower results comparatively 
than small sections. 

Increase of density and strength generally follows an in- 
crease of static pressure in the mold. 

As a rule, test bars should be cast in the vertical position. 

Brass and nickel alloys should have a riser attached. 

Owing to the tendency of tin to segregate, some gun metal 
— copper and tin — mixtures give better results when the bars are 
cast in the horizontal position. 

When a test bar is specified to be cast on a casting, the 
best results are obtained when the bar is about the same sec- 
tional area as that part of the casting to which it is connected, 
and also when it is as far away from the main body of metal as 




Fig. 40 — Vertical, hydraulic testing machine 




Fig. 41 — Impact testing machine 



Testing Alloys 183 



possible. This insures a uniform cooling rate, and more truly 
indicates the character of the casting at that particular part. 

Rounded corners and very gradual changes of section are 
advisable for all bars that have to undergo tensile, torsional or 
elasticity tests. 

Test pieces should not be cast on the top part of a casting. 
They only act as risers, collecting dirt, and are likely to contain 
flaws. 

The principal test should always be the one which most 
closely resembles the strains that the alloy will have to stand 
when in actual use. 

All the variations in strains, pressures and speeds that cast- 
ings are subject to in practical use, cannot be reproduced on a 
testing machine, but the physical tests taken in conjunction with 
the microscopical and chemical deductions, afford ample infor- 
mation for the safe amount of burden that may be imposed on 
the alloy. 

The casting temperature of alloys is of greater importance 
than the rate of cooling, although both conditions exert a power- 
ful influence on the physical properties of the castings. With 
cast iron, variations in the rate of cooling have more pro- 
nounced effects than variations in the casting temperature. With 
alloys, especially of copper, the casting temperature is of par- 
amount importance. 



184 



Practical Alloying 



PARTICULARS OF ALL THE KNOWN METALS 















Electrical 


Heat 








Atomicity, 




Specific 


conduc- 


conduc- 


Metal 


Symbol 


Color 


new 


Specific 


heat 


tivity 


tivity 








system 


gravity 


at Cent. 


mercury 
at Cent. 


silver 
= 100 


Aluminum 


Al 


Tin-white 


.271 


2.56 


.2253 


20.97 


31.33 


Antimony 


Sb 


Silver-white 


120.43 


6.697 


.0523 


2.05 


4.03 


Arsenic 


As 


Steel-grey 


75.01 


5.727 


.083 


2.679 




Barium 


Ba 


Ylwsh.-white 


137.43 


3.5-4 








Bismuth 


Bi 


White 


208.11 


9.759 


.0305 at 20° 


.8676 


1.8 


Cadmium 


Cd 


White, blue 
tinge 


112.3 


8.65-8.8 


.0548 


13.46 


20.06 


Ceesium 


Cs 


Silver-white 


132.9 


1.88 








Calcium 


Ca 


Ylwsh.-white 


40 


1.82 


.1686 


12.5 


25.4 


Cerium 


Ce 


Steel-grey 


140 


5.5 


. 04479 






Chromium 


Cr 


Greyish-white 


52.45 


6.8-7.3 


.0998 






Cobalt 


Co 


Steel-grey 


58.8 


8.52-8.95 


.107 


9.685 


17.2 


Copper 


Cu 


Reddish-ylw. 


63 


8.36-8.95 


. 0933 


52 to 64 


73.6 


Didymium 


Di+Pr 


White 


142 


6.544 


.04563 






Erbium 


Er 




166 










Gallium 


Ga 


Silver-white 


70 


5.96 


.079 






Germanium 


Ge 


Greyish-white 


72.3 


5.469 


.0737 






Glucinum* 


BeorGl 


Steel-colored 


9.08 


2.1 


.4702 






Gold 


Au 


Yellow 


196.5 


19.3 


.0316 


43.84 


S3. 2 


Indium 


In 


Silver-white 


113.4 


7.4 


.05695 






Iridium 


Ir 


Grey 


192.5 


22.38 


.0323 






Iron 


Fe 


Greyish-white 


56 


6.95-8.2 


.114 


9.6S 


11.9 


Lanthanum 


La 


White 


138.5 


6.163 


. 04485 






Lead 


Pb 


Blue-grey 


206.4 


11.4 


.03065 


4.8 


8.5 


Lithium 


Li 


Silver-white 


7.03 


0.578-0.589 


.9408 


10.65 




Magnesium 


Mg 


Silver-white 


24.36 


1.75 


20°-5 1.245° 


22.84 


■34.3 


Manganese 


Mn 


White-grey 


55.02 


8 


14°-97° 






Mercury 


Hg 


White 


200 


13.6 


.033 


.1 


S.3 


Molybdenum 


Mo 


Dull silver 


96. 


8.62 


.0659 






Neodymium 


Nd 




143.6 










Nickel 


Ni 


White 


58.7 


8.3-8.7 


.10916 


7.374 




Niobiumf 


Nb 


Steel-grey 


94 


4.06 








Osmium 


Os 


Blue-white 


190.8 


22.477 


.03113 






Palladium 


Pd 


White 


106.5 


11.4 


.0582 






Platinum 


Pt 


White 


194.5 


21.5 


.0314 


8.043 
Ag=100 


17.9 


Potassium 


K 


Silver-white 


39.04 


0.875 


.166 


11.23 


45 


Praseodymium Pr 




140.5 




.0314 






Rhodium 


Rh 


Bluish-white 


102.7 


12.1 


. 05803 






Rubidium 


Rb 


White 


85.2 


1.52 








Ruthenium 


Ru 


White 


101.4 


12.261 


.0611 






Samarium 


Sm 




150 










Scandium 


Sc 




44 










Silver 


Ag 


White 


107.66 


10.4-10.7 


.0557 


63.84$ 


100 


Sodium 


Na 


Silver-white 


22.995 


0.9735 


.2734 


18.3 


Sfi.t 


Strontium 


Sr 


Ylwsh.-white 


87.3 


2.542 








Tantalum 


Ta 




183 


10.8 








Tellurium 


Te 


White shin- 
ing semi- 
metal 


127.49 


6.255 


.0475 


. 000777 

AgatO* 

= 1 




Terbium 


Tr 




160 










Thallium 


Tl 


White 


203.64 


11.88 


.0325 


5.225 




Thorium 


Th 


Greyish-white 


232 


11.1-11.23 


. 02787 






Tin 


Sn 


Silver-white 


119 


7.3 


.0559 


8.726 


1*2 


Titanium 


Ti 


Dark-grey 


47.9 


3.5888 


.1135 






Tungsten 


W 


Steel-grey 


184.4 


18.77 


.035 






Uranium 


U 


Silver-white 


240 


18.7 


.0276 






Vanadium 


V 


Light-grey 


51.4 


5.5 








Ytterbium 


Yb 




173 










Yttrium 


Y 




89 










Zinc 


Zn 


Bluish-white 


65.4 


6.9-7.15 


.0935 


16.4 


28.1 


Zirconium 


Zr 


Grey 


90.5 


4.15 


.066 







•Also called bervllium 



fAlso called columbium 



Tables, etc. 


185 


CONTRACTION OF METALS IN 


COOLING 


In fractions of 
Metal linear dimensions 


In parts of an inch per 
foot of linear dimensions 



Cast iron 
Gun metal 
Yellow brass 
Copper 
Zinc and tin 
Lead 






h 
A 



i 



s 

A 



CONTRACTION OF CASTINGS 



Inch 



Thin brass 

Thick brass . 

Gunmetal rods 

Zinc .... 

Copper 

Bismuth 

Tin and lead, each 

Aluminum 

Delta metal . 

Manganese bronze 



f in 9 inches 

\ in 10 inches 

| in 9 inches 

x\ per foot 

j% per foot 

s 5 2 per foot 

\ per foot 

\\ per foot - 

T s g per foot 

\ per foot 



When a substance \ 1 in the act of fusion, the solid 

( contracts J 

parts will ) . I in the liquid. Such substances have their 
temperature of fusion -j (. while under pressure. Ex- 



ample : 



cast iron 
water 



For a rise of 10 degrees Fahrenheit (5.5 degrees Centigrade)- 



Iron expands about 
Steel expands about 
Copper expands about 
Brass expands about . 



T7fff0 

Wott 



186 



Practical Alloying 



TABLE OF SPECIFIC GRAVITY, WEIGHT PER CUBIC 

INCH, SPECIFIC HEAT, LATENT HEAT OF 

FUSION, AND APPROXIMATE MELTING 

POINTS OF METALS 







Grams 




Latent 


Melting 






Specific 


per cubic 


Specific 


heat of 


point 


Authority for 


Name 


gravity 


inch 


heat 


fusion 


Cent. 


melting points 


Aluminum 


2.6 


42.62 


.222 


80 


625 


Roberts-Austin 


Antimony 


6.8 


111.48 


.051 


16 


432 


Pouillet 




9.8 


160.66 


.031 


12.4 


268.3 


Rudberg 




8.66 


141.97 
109.02 
142.62 
145.90 


.055 
.100 
.107 
.095 


13.1 

68" 
43 


320.7 
1515 
1500 
1054 






6.65 




Cobalt 


8.7 


Pictet 




8.9 


Violle 


Gold 


19.33 


316.89 


.032 


16.3 


1045 


Violle 




22.42 


367.55 


.033 


28 


1950 


Violle 




7.8 


127.87 


.112 


69 


1600 


Pictet 




11.35 


186.07 


.032 


5.4 


326.2 


Person 


Magnesium 


1.71 


28.03 


.245 


58 


750 






7.39 


121.15 
222.79 


.122 
.032 


'2.8 


1245 
—39.5 






13.59 


Regnault 




8.6 


140.98 


.108 


68 


1484 


Bredig 




22.47 


368.37 


.031 


35 


2500 


Pictet 




11.4 


186.89 
352.47 


.059 
.032 


36.3 
27.2 


1587 
1780 






21.5 


Bredig 




12.10 


198.37 


.058 


52 


2000 


Pictet 




12.26 


200.99 


.061 


46 


2000+ 


Deville & Debray 




10.53 


172.62 


.057 


24.7 


961.5 


Bredig 


Tin 


7.3 


119.67 


.056 


14.5 


232.7 


Person 




3.58 


58.69 


.113 




3000 






18.77 


307.71 


.035 




1700 






6.9 


113.12 


.096 


22.6 


419 


Bredig 



TABLE SHOWING METALS IN ORDER OF MALLEABIL- 
ITY, DUCTILITY AND TENACITY 



Malleability 



Ductility 



Tenacity 



Gold 

Silver 

Aluminum 

Copper 

Tin 

Platinum 

Lead 

Iron 

Zinc 



Gold 

Platinum 

Silver 

Aluminum 

Iron 

Copper 

Zinc 

Tin 

Lead 



Iron 

Copper 

Platinum 

Silver 

Aluminum 

Gold 

Zinc 

Tin 

Lead 



Tables, etc. 



187 



TABLE OF THE WEIGHT, IN POUNDS, PER FOOT IN 
LENGTH OF GUN METAL. 

Composition: Copper, 9 parts; Tin, 1 part 



Side of the 
square or 
diameter 



Square 



Hexagon 



Octagon 



Circle 



M 875 

% 1.967 

1 3.500 

1M 5.467 

iy 2 7.875 

1% 10.717 

2 14.000 

2M 16.717 

iy 2 21.875 

2M 26.467 

3 31.500 

3M 36.967 

V/ 2 42.875 

3% 49.217 

4 56.000 

4M 63.217 

Qi 70.875 

ifi/i 78.967 

5 87.500 

5M 96.467 

5K 105.875 

m 115.717 

6 126.000 

6M 136.717 

6H 147.875 

6% 159.467 

7 171.500 

7J4 183.967 

iy % 196.875 

7% 210.217 

8 224.000 

8M 238.217 

%y 2 252.875 

%% 267.967 

9 283.500 

9M 299.467 

Q}4 315.875 

9% 332.717 

10 350.000 

10% 367.717 

10H 385.875 

10% 402.467 

11 423.500 

11% 442.968 

113^ 462.875 

11% 483.217 

12 504.000 



.756 
1.711 

3.027 
4.732 
6.814 
9.275 
12.113 
15.333 
18.928 
22.904 
27.261 
31.993 
37.107 
42.605 
48.464 
54.715 
61.341 
68.344 
75.729 
83.492 
91.633 
100.152 
109.053 
118.328 
127.984 
138.019 
148.431 
159.222 
170.394 
181.744 
193.872 
206.178 
218.862 
231.927 
245.367 
259.189 
273.392 
287.969 
302.928 
318.258 
333.977 
350.066 
366.541 
383.393 
400.617 
418.124 
436.212 



,728 
1.648 
2.915 
4.553 
6.559 
8.928 
11.662 
14.749 
18.207 
22.032 
26.222 
30.772 
35.693 
40.971 
46.616 
52.629 
59.003 
65 . 740 
72.845 
80.307 
88.140 
96.337 
104.895 
113.816 
123.111 
132.758 
142.775 
153.153 
163.898 
175.010 
186.483 
198.320 
210.541 
223.090 
236.019 
249.312 
262.969 
276.993 
291.382 
306.131 
321.247 
336.724 
352.572 
368.781 
385.350 
402.290 
419.587 



1.554 
2.747 
4.294 
6.184 
8.417 
10.993 
12.916 
17.178 
20.786 
24.738 
29.034 
34.273 
38.654 
43.981 
49.651 
55.664 
62.020 
68.722 
75.764 
83.153 
90.884 
98.959 
107.376 
116.140 
125.244 
134.694 
144.487 
154.623 
165.105 
175.927 
187.096 
198.607 
210.462 
222.659 
235.200 
248.087 
261.317 
274.890 
288.802 
303.065 
317.667 
332.615 
347.907 
363.538 
379.519 
395.839 



188 



Practical Alloying 



The following table gives the weights of most ordinary 
metals and alloys: 



Weight per 
Metal cubic inch, pounds 

Copper 318 

Nickel 318 

Zinc 248 

Aluminum .093 

Lead 410 

Antimony . 242 

Tin 264 

Gun metal 315 

Brass .3 

Magnolia .376 



< Weight 

in pounds 

per cubic foot 



Weight of 1 
square foot, 1 inch 
thick, in pounds 



549 


46 


518 


45 


429 


37*5 


160 


14 


710 


60 


420 


35 


456 


38 


544 


UK 


520 


43 


650 


54 



The lightness of aluminum is best illustrated by the follow- 
ing table, comparing it with other metals.* 



Weight 
Specific per cubic ft. 

gravity pounds 



Volume per lb. 
weight in 
cubic feet 



Relative 

Spec. Gr. 

Al = l 



Aluminum 2.56 

Antimony 6. 72 

Zinc 7 

Iron 7.23 

Tin 7.29 

Steel 8 

Copper 8.6 

Bismuth 9.82 

Silver 10.47 

Lead 11.36 

Mercury 13.60 

Gold 18.41 

Platinum 21.53 



160 


0.00625 


1.000 


420 


0.00238 


2.625 


437 


0.00229 


2.734 


451 


0.00222 


2.824 


455 


0.00220 


2.848 


499 


0.00200 


3.125 


537 


0.00186 


3.859 


613 


0.00163 


3.836 


654 


0.00153 


4.090 


709 


0.00141 


4.438 


849 


0.00118 


5.312 


1150 


0.00087 


7.191 


1344 


0.00074 


8.410 



TABLE SHOWING THE ALLOYS WHOSE DENSITY 
GREATER (+ ) OR LESS (— ) THAN THE 
MEAN OF THEIR CONSTITUENTS 



IS 



+ Alloys 



Alloys 



Gold and zinc 
Gold and tin 
Gold and bismuth 
Gold and cobalt 
Gold and antimony 
Silver and zinc 
Silver and bismuth 
Silver and antimony 
Copper and zinc 
Copper and tin 
Copper and lead 
Copper and bismuth 
Lead and antimony 
Platinum and molybdenum 



Gold and silver 
Gold and iron 
Gold and lead 
Gold and copper 
Gold and iridium 
Gold and nickel 
Silver and copper 
Iron and bismuth 
Iron and antimony 
Iron and lead 
Tin and lead 
Tin and antimony 
Nickel and arsenic 
Zinc and antimony 



*Glucinum is lighter than aluminum and equally durable, a better conductor 
of electricity than copper or even silver, and stronger than iron. Only the ex- 
pense of production prevents this metal proving of great industrial value. 



Tables, etc. 



189 



PROPERTIES OF ALLOYS 



Specific 

Alloys gravity 

Aluminum bronze (5% Al) 7. 68 

Brass (tube) (67:33) 8. 43 

Brass (cast) (2:1) 8.4 

Naval brass (rod) 

Muntz metal (rolled) 8. 405 

Delta metal (rolled) 8.45 

Gun metal (88:12) 8.56 

Phosphor bronze 8 . 60 

Steel (average) 7 . 85 

Iron (No. 3 Pig) 7.126 

Iron (No. 1 Pig) (cold blast) 7. 137 

Aluminum brass (2% Al) 8.33 

Babbitt's alloy 7.5 



Weight 
of a 

cubic foot 
in pounds 



Tenacity in 
pounds per 
square inch 



Crushing Melting 

force in point, 

pounds per degrees 

square inch 



Fahr. 



480 


71,680 


526 


26,600 


525 


17,978 




60,480 


524 


62,720 


527 


91,800 


534 


36,500 


536.8 


38,208 


489.5 


120,000 


444.6 


21,859 


446 


23,257 




70,000 


450 


9,000 



10,300 



91,661 
95,775 



16,000 



1900 

1800 
1832 

1850 
1900 
1800 
3250 



440 



Dr. J. Ure's rule for calculating the specific gravity of an 
alloy : 

(W— w) P P 



M 



Pw + P W 



M is the mean specific gravity of the alloy, W and w the 
weights, and P and p the specific gravities of the constituent 
metals. 



TO FIND THE WEIGHT OF A CASTING FROM THAT OF 
THE PATTERN 



A pattern weighing 

one pound Will Weigh When Cast In 

Cast iron Yellow brass Gun metal Zinc Copper Aluminum 

Baywood 8.8 9.9 10.3 8.5 10.5 3.2 

Beech 8.5 9.5 10. 8.2 10.1 3.1 

Cedar 16.1 18. 18.9 15.6 19.2 5.8 

Cherry 10.7 12. 12.6 10.4 12.8 3.9 

Linden 12. 13.5 14.1 11.6 14.3 4.3 

Mahogany 8.5 9.5 10. 8.2 10.1 3.1 

Maple 9.2 10.3 10.8 8.9 11. 3.2 

Oak 9.4 10.5 11. 9.1 11.2 3.4 

Pear 10.9 12.2 12.8 10.6 13. 3.9 

Pine, white 14.7 16.5 17.3 14.3 17.5 5.3 

Pine.yellow 13.1 14.7 15.4 12.7 15.6 4.7 

Whitewood 16.4 18.4 19.3 15.9 19.5 5.9 

Allowance must be made for the metal in the pattern. 

Reduction for Round Cores and Core Prints 

Rule. — Multiply the square of the diameter by the length of the core and prints in inches, and 

the product by 0.014. This will give the weight of the white pine core, to be deducted from the weight 
of the pattern. 



INDEX 

About crucibles 174 

Acid bronze 146 

Air furnace charges containing scrap 122 

Ajax bronze 120 

Alchemists, work of the 5 

Alligator cracks 176 

Alloy, anti-friction 39 

Alloy, definition of 18 

Alloy for bells 132 

Alloy, for fittings for ships 132 

Alloy for nickel coinage 21 

Alloy for scientific instruments 149 

Alloy, imitation silver 71 

Alloy, Lipowitz's 140 

Alloy of copper and iron SO 

Alloy, pale gold 126 

Alloy, standard, electrical resistance 84 

Alloy, statuary bronze 71 

Alloy, Wood's 140 

Alloying by concentrates 41 

Alloying by the Ancients 53 

Alloying, difficulties of 45 

Alloying metals, reasons for 25 

Alloying, some difficulties of 41 

Alloys, -aluminum brass 57 

Alloys, aluminum, light 99-135 

Alloys, art metal 148 

Alloys at critical temperatures 36 

Alloys, brass, for castings 83 

Alloys, brass founders', typical 121 

Alloys, color action of metals in 70 

Alloys, color of 65-68 

Alloys, confusion of notation 75 

Alloys containing mercury 148 

Alloys, dual , 23-112 

Alloys, dissolving metals out of 67 

Alloys, eutectic 38 



192 



Index 



Alloys, fluxes for 150 x 

Alloys, gates and risers for 163 

Alloys, German silver 84 

Alloys, hard solders for 143 

Alloys, history and peculiarities of 14 

Alloys in bronze 44 

Alloys, light 96 

Alloys, magnalium 97 

Alloys, magnesium 148 

Alloys, melting 55 

Alloys, methods of making 52 

Alloys, miscellaneous 146 

Alloys, modern bronze 85 

Alloys, nickel 96 

Alloys, non-oxidizable 71 

Alloys, notation of 73 

Alloys, pattern metal 97 

Alloys, peculiar properties of 35 

Alloys, physical characteristics of 49 

Alloys, properties of 25-189 

Alloys, range of elements in 124 

Alloys, remelting 47-54 * 

Alloys, shipbuilders' 130 

Alloys, specimen, from new metals 123 

Alloys, standard 80 

Alloys, standard, from mixed metals 119 

Alloys, structure of, affected by casting temperature 36 ' 

Alloys, Susini's 96 

Alloys, systematic notation for 78 

Alloys, tenacity of . . ". 189 

Alloys, testing 181 

Alloys, 'tests of, effects of variations in casting temperatures. . . 37 

Alloys, white, for art castings 149 

Alloys, working properties of 30 

Alloys, zinc-aluminum 97 

Aluminum 56-92-154 

Aluminum alloys for automobile castings 132 

Aluminum alloys for castings 99 

Aluminum alloys, fusible hard solder for 143 

Aluminum alloys, light 99-135 

Aluminum and zinc 92 

Aluminum as a flux 56 

Aluminum as a pattern metal 135 

Aluminum bell metal 97 



Index 193 

Aluminum brass 100 

Aluminum brass alloys 57-95 

Aluminum bronze 26-75-93-98 

Aluminum silver 99 

Aluminum, soft solder for 143 

Aluminum solders 136 

Aluminized-zinc 153 

Amalgams, dentists' 141 

Amalgam, Mackenzie's 141 

Amalgam, zinc 143 

Annealing crucibles 175 

Anti-acid metal 90-116-121 

Anti-friction alloy 39 

Anti-friction alloys, compounding 110 

Anti-friction alloys, melting 59 

Anti-friction brasses 146 

Anti-friction lining metal 149 

Anti-friction metals 101 

Anti-friction metals, cheap 117 

Anti-friction metals for use in ships 130 

Anti-friction metals, overheating 114 

Anti-friction metals, Pennsylvania railroad tests 103 

Anti-friction metals, white, classification of 107 

Anti-friction paste 117 

Antimonial lead 91-153 

Antiquity of the softer metals 2 

Anti-rust alloy 146 

Anti-rust metal 132 

Argentan 148 

Argentan alloys 93 

Armor plate bronze 132 

Arsenic 155 

Arsenic bronze 104-155 

Arsenic lead 153 

Art castings, alloy for 83 

Art castings, white alloy for 149 

Art metal alloys 148 

Art metal mixtures 138 

Ash metal 119-123 

Ash metal, analysis of , 124 

Aurichalcum 53 

Automobile castings, aluminum alloy for 132 

Babbitt's alloys ' 112 

Babbitt's hardening 113 



194 Index 

Babbitt's metal 107 

Babbitt metal, commercial 101 

Babbitt metal, genuine 73 

Babbitt metal, how to make 115 

Babbitt mixture, special 116 

Babbitt, the man and the metal 112 

Bearing bronze , 78-85 

Bearings, bronze alloy for 85 

Bearing metal mixtures 104 

Bearing mixtures, impurities in 110 

Bell metal 78-85 

Bell metal, aluminum 97 

Bell metal, new 146 

Bells, alloy for 132 

Bismuth 30 

Bismuth in anti-friction metals 109 

Bolts, alloy for 83-85 

Box metal 103 

Brass alloys for castings 83 

Brass, aluminum 100 

Brass, brazing 83 

Brass casting on iron 167 

Brass, dipping 68-83 

Brass, fine 83 

Brass, fine, tensile strength of 82 

Brass, hard white 149 

Brass, hard solders for 143 

Brass, high 83 

Brass, malleable 83 

Brass, naval 83 

Brass, red 83 

Brass solders 143 

Brass, tensile strength ri 82 

Brass, tough alloy for bending 149 

Brass, turnery 83 

Brass, white 83-136 

Brass, yellow 83 

Brasses, anti-friction 146 

Brasses, engine, gate for 168 

Brasses, locomotive, alloy for 85 

Brasses, mill, alloy for 85 

Brazing brass 83 

Brazing metal, how to make 120 

Brazing solder 83 

Brazing solder, method of granulating 144 



Index 195 

Bright dipping acid 126 

Britannia metal 140 

Bronze, acid 146 

Bronze alloy for bearings 85 

Bronze alloys 44 

Bronze alloys, modern 85 

Bronze, aluminum 75-98 

Bronze, armor plate 132 

Bronze, cobalt 146 

Bronze, colors of 69 

Bronze, definition of 16 

Bronze, deoxidized 85 

Bronze, high tension 95 

Bronze in the World's history 15 

Bronzes, non-oxidizable 145 

Bronze, platinum 146 

Carbon 26 

Casting brass on iron 167 

Casting temperatures, affect on structure of alloys 36 

Casting temperatures, affects of variations 37 

Casting, to find weight of from pattern 189 

Castings, aluminum alloys for 99 

Castings, art, alloys for 83 

Castings, brass, alloys for 83 

Castings, contraction of 185 

Castings, ornamental 83 

Castings, ornamental, red brass for 149 

Chandelier work, mixtures for 125 

Charpy's alloy 149 

Chemical bronze 127 

Chemistry and metallurgy 5 

Cobalt bronze 146 

Coefficients of friction 106 

Color action of metals in alloys 70 

Color effects, mechanical 67 

Color of alloys 65-68 

Color of metals 184 

Color, uniformity of 69 

Colors of bronze 69 

Columnar fracture 33 

Combination of metals 21 

Compounding anti-friction alloys 110 

Conchoidal fracture 33 

Conductivity 35 



196 Index 

Confusion of notation of alloys 75 

Cupola melting 61 

Core gate 170 

Corinthian copper 17 

Corrosion of metals 157 

Contraction of metals in cooling 185 

Contraction of castings 185 

Copper, Corinthian 17 

Copper castings, high electrical efficiency 156 

Copper and iron alloy 50 

Copper-zinc alloys, tests of 37 

Cowles' silver bronze 93 

Cracks, alligator 176 

Crucibles 174 

Crucibles, alligator cracks in 176 

Crucibles, capacity and shape of 176 

Crucibles, ground 180 

Crucible, squeezed 176 

Crucible, scalped 175 

Crucibles, proper annealing of 175 

Crucibles, pin-holes in 176 

Crucibles, some uses of old 177 

Crystalline, definition of 43 

Crystalline fracture 33 

Crystallization 38 

Decorative processes 66 

Definition of alloy 18 

Definition of bronze. 16 

Delta metal 54-431 

Delta metal, tensile strength of 82 

Damascus metal 132 

Dentists' amalgams 141 

Density 29 

Deoxidized bronze 85 

Difficulties of alloying 41-45 

Dipping acid, bright 126 

Dipping acid, fumeless 126 

Dipping brass « 68-83 

Dip to blacken aluminum 126 

Disparity in melting points of metals 57 

Dissolving metals out of alloys 67 

Dual alloys 23-112 

Ductility, metals in order of 186 

Dynamos, anti-friction metal for 116 



Index 197 

Electrical conductivity of metals 184 

Electrical efficiency, copper castings of high 156 

Electrical reduction of ores 11 

Electrical resistance alloy 84 

Electrical resistance, high, white alloy for 34 

Electro-conductivity 13 

Electro-technology 12 

Elements in alloys, range of 124 

Engine brasses, gate for 168 

Eutectic alloys ; 38 

Expansion of metals 185 

Farquharson's alloy 83 

Ferro-aluminum 153 

Ferro-manganese 153 

Ferro-nickel 18 

Ferro-zinc 153 

Fibrous fracture 33 

Fine brass 83 

Fittings for ships, alloy for 132 

Flanges, alloy for 83 

Florentine bronzes 83 

Fluidity of metals 155 

Flux, aluminum as a 56 

Flux for welding copper 157 

Flux for alloys 150 

Fluxes for aluminum alloys 152 

Fluxes for babbitt metals 152 

Fluxes for brass 151 

Fluxes for brass sweepings 152 

Fluxes for brazing metals 152 

Fluxes for britannia metals 152 

Fluxes for copper 152 

Fluxes for copper alloys 152 

Fluxes for German silver 152 

Fluxes for gun metals 151 

Fluxes, metallic 153 

Fluxes for nickel alloys 152 

Fluxes for zinc alloys 152 

Fluxes, use of metalloids as 156 

Foundry mixtures 118 

Fracture 32 

Fracture, columnar 33 

Fracture, conchoidal 33 

Fracture, crystalline 33 



198 Index 

Fracture fibrous 33 

Fracture, grading by 49 

Fracture granular 33 

Fractures 34 

Fractures, metallic, classification of . . . . 33 

Friction, coefficients of 106 

Friction, definition of 105 

Fuels for melting brass 63 

Fumeless dipping acid 126 

Fusible solder 140 

Fusibility of alloys 28 

Fusibility, surfaces of 4# 

Gate, core 170 

Gate for engine brass 168 

Gate, skimming 165 

Gates for alloys 163 

Gating a blank gear 167 

Gating a blank gear, four different methods of 167 

Gating a stair tread 167 

Gating brass valve seats 167 

Gating castings, pointers on 171 

Gating electric drill cover when cast in aluminum 165 

Gating, improper method of 164 

Gating liners and gun metal rolls 166 

Gating, method of, an electric drill cover 165 

Gating, proper method of 164 

Gear blank, method of gating 167 

Genuine babbitt metal 73 

German silver 78 

German silver alloys 84 

Gilding alloys 83 

Glass, solder for 142 

Gold lacquer 127 

Gold solders 141 

Golden copper 53 

Goodman's investigations 108 

Grading by fracture 49 

Granular fracture 33 

Green lacquer for bronze 127 

Gun metal 85 

Gun metal alloys 94 

Gun metal, color of 69 

Gun metal for high steam pressures 90 

Gun metal for piston rings ... 149 

Gun metal for springs 149 

Gun metal, weight of per foot 187 



Index 199 

Hard solders 141 

Hard solder for bell metal 149 

Hard white brass 149 

Hardening 54- 

Hardening, Babbitt's 113 

Hardening for gun metal 94 

Hardness 26 

Hardness, relative, of metals 27 

Heat conductivity of metals 184 

Hepatizon 17 

Heusler's magnetic alloy 146 

High brass 83 

High tension bronze 95 

Hinges, alloy for 83 

History and peculiarities of alloys 14 

Horn gate, method of casting a pinion with a 169 

Hydraulic castings, alloy for 85 

Imitation silver 93 

Imitation silver alloy 71 

Impurities in bearing mixtures 110 

Irido-platinum 91 

Iron 84 

Iron and copper alloy 50 

Iron, casting brass on 167 

Japanese pickling solution 71 

Kreusler's alloy for bearings 149 

Kunzel's alloy 103 

Lacquer, gold 127 

Lacquer, green, for bronze 127 

Lacquer, silver 127 

Lacquers 126 

Ladle, self-skimming 178 

Latent heat of fusion 186 

Lead, affect on aluminum 92 

Lead in anti-friction metals 109 

Light alloys 96 

Light aluminum alloys 99 

Liners, method of gating 166 

Lining metal, anti-friction 149 

Lipowitz's alloy 140 

Liquation of metals 44 

Locomotive bearings, plastic bronze for 132 

Locomotive brasses, alloy for 85 

Lumen bronze 132 



200 Index 

Machine, testing, impact 181 

Machine, testing, vertical, hydraulic 181 

Mackenzie's amalgam 141 

Magnalium 99-153 

Magnalium alloys 97 

Magnalium, Murman's improved 149 

Magnesium 56 

Magnesium alloys 148 

Magnesium-aluminum alloys 93 

Malleable brass 83 

Malleability, metals in order of 186 

Manganese 155 

Manganese babbitt metal 117 

Manganese bronze, Parsons' 100 

Manganese bronze propellers 100 

Manganese-copper 153 

Manganin 84 

Marine brass mixtures 127-128 

Marine engines, anti-friction metals for 116 

Mechanical color effects 67 

Melting alloys 55 

Melting anti-friction alloys 59 

Melting in the cupola 61 

Melting points of metals 186 

Melting points of metals, disparity in 57 

Melting ratios 59-62 

Mercury, alloys containing 148 

Metal refining, ancient and modern 1 

Metallic combinations 7 

Metallic fractures, classification of 33 

Metallic fluxes 153 

Metalloids, use of as fluxes 156 

Metallurgy and chemistry 5 

Metals, anti-friction 101 

Metals, color of 184 

Metals, combination of 21 

Metals, contracting of in cooling 185 

Metals, corrosion of 157 

Metals, electrical conductivity of 184 

Metals, expansion of 185 

Metals, fluidity 'of 155 

Metals, heat conductivity of 184 

Metals, liquation of 44 

Metals, melting points of 186 

Metals, new, specimen mixtures from 123 



Index 201 

Metals, novelty 147 

Metals, oxidation of 45 

Metals, particulars of all known 184 

Metals, properties of in relation to friction 109 

Metals, relative conductivity of 35 

Metals, relative hardness of 27 

Metals, specific gravity of 184 

Metals, specific heat of 186 

Metals, tests for 182 

Metals, weights of 188 

Metals, weight per cubic inch 186 

Metals, working properties of 30 

Meteorite 99-136 

Methods of making alloys 52 

Metric standards, alloy for 92 

Mill brasses, alloy for 85 

Miscellaneous alloys 146 

Mixtures, art metal 138 

Mixtures for propellers 129 

Mixtures, foundry 118 

Mixtures, marine brass 127-128 

Mixtures, scrap in 120 

Mixtures, special 149 

Mixtures, white brass 137 

Mixtures, white metal, special 138 

Mock silver alloy 99 

Mold, arrangement of, for casting brass on iron 168 

Mold, cross-section of showing core gate 170 

Mourey's solder 147 

Muntz metal, tensile strength of 82 

Murman's improved magnalium 149 

Murman's patent 99 

Naval brass 83 

Nickel alloys 96 

Nickel-aluminum alloys 93 

Nickel bronze 130 

Nickel coinage alloy 21 

Nickelumen 93 

Nickel, use of in German silver 84 

Niello-silver 71 

Non-oxidizable alloys 71 

Non-oxidizable bronzes 145 

Notations of alloys 73 

Notation, systematic 77 



202 Index 

Notes on test bars 182 

Novelty metals 147 

Old metals in foundry mixtures 120 

Ores 6 

Ores complex, treatment of 10 

Ores, electrical reduction of 11 

Ore, methods of extracting metals from 9 

Ores, treatment of 7 

Ornamental castings 83 

Overheating anti-friction metals 114 

Oxidation of metals 45 

Pale gold alloy 126 

Panels, alloy for 83 

Parsons' manganese bronze 100 

Partinium 99 

Paste, anti-friction 117 

Pattern metal alloys 97 

Pattern metal, aluminum as a 135 

Pattern metal mixtures 134 

Pattern metals, properties of 134 

Peculiar properties of alloys 35 

Pennsylvania railroad tests of anti-friction metals 103 

Pewter - ■ • 140 

Phosphor-aluminum 153 

Phosphor bronze 86 

Phosphor bronze, peculiarities of S6 

Phosphor bronze, suggestions for melting 88 

Phosphor-copper 153 

Phosphor-tin 153 

Phosphorus 84-87-88-154 

Phosphorus-aluminum 27 

Physical characteristics of alloys 49 

Pickle for brass castings 127 

Pin-holes in crucibles 176 

Pinion, method of casting with a horn gate 169 

Piston rings, gun metal for 149 

Plastic bronze 105 

Plastic bronze for locomotive bearings 132 

Plastic metal 132 

Platinum bronze 146 

Plug head 169 

Plumbers' solder 7S 

Polished brass work, alloy for 83 

Pottery, solder for. , 142 



Index 203 

Propeller blade, casting in a vertical position 170 

Propellers, alloy for 85 

Propellers, manganese bronze 100 

Propellers, mixtures for 129 

Properties of alloys 25-189 

Pump rods, alloy for 83 

Pumps, alloy for 83 

Pumps, chemical, alloy for 85 

Ratios, melting 59-62 

Red brass 83 

Red brass for ornamental castings 149 

Relative conductivity of metals 35 

Remelting alloys 47-54-84 

Risers !69 

Risers for alloys 163 

Rolls, gun metal, method of gating 166 

Romanium 99 

Rozine for castings 146 

Rozine for jewelry 146 

Rozine for springs 14-6 

Ruebel's patent 99 

Scalped crucible 175 

Scrap in air furnace charges 122 

Scrap in foundry mixtures 120 

Shipbuilders' alloys 130 

Ship fastenings, alloys for 83 

Sibley casting alloy 135 

Silicon bronze 78 

Silicon-copper 183 

Silver-aluminum alloys 93 

Silver bronze, Cowles' 93 

Silver, imitation 93 

Silver lacquer 127 

Silver solders 142 

Silver, sterling 18 

Skimming gate 165 

Slabs for pulverizing, alloy for 83 

Soft solders 139 

Solder, brazing 83 

Solder, brazing, method of granulating 144 

Solder, fusible 140 

Solder, hard, for bell metal 149 

Solder, hard fusible, for aluminum alloys 143 



204 Index 

Solder, Mxmrey's 147 

Solder, soft for aluminum 143 

Solder without heat 147 

Solders, aluminum 136 

Solders, brass 143 

Solders for glass and pottery • 142 

Solders, gold 141 

Solders, hard 141 

Solders, hard, for brass and alloys 143 

Solders, silver • • • • 142 

Solders, soft 139 

Solders, spelter 143 

Solution, Japanese pickling 71 

Sorel's alloys 137 

Special mixtures 149 

Specific gravity 29 

Specific gravity of metals 184-188 

Specific gravity, rule for calculating 189 

Specific heat of metals 186 

Spelter solders 143 

Spindles, alloy for 83 

Springs, gun metal for 149 

Stair tread, method of gating 167 

Stanchions, alloy for , 83 

Standard alloys 80 

Statuary bronze alloy 71 

Steam metal 78-85-90 

Sterling silver 18 

Sterro metal, tensile strength of 82 

Stirrer, plumbago 180 

Sun metal 78 

Surfaces of fusibilty 40 

Susini's alloys 96 

Systematic notation 77 

Systematic notation for alloys 78 

Table of alloys whose density is greater or less than the 

means of their constituents 188 

Tables, etc 184 

Tenacity, metals in order of 186 

Tenacity of alloys 189 

Tensile strength of brass 82 

Tensile strength of Delta metal S2 

Tensile strength of fine brass 82 

Tensile strength of Muntz metal 82 



Index 205 

Tensile strength of Sterro metal 82 

Test bars, notes on 182 

Testing alloys 181 

Testing machine, impact 181 

Testing machine, vertical hydraulic 181 

Tests for metals 182 

Tier's argent 26 

Tin-aluminum alloys 93 

Taps, alloys for 83 

Treatment of complex ores 10 

Treatment of ones 7 

Turnery brass 83 

Type metal 78 

Uniformity of color of alloys 69 

Unions, alloy for 83 

Universal bearing metal 116 

Valve seats, brass, method of gating 167 

Venus metal 71 

Weight of gun metal per foot 187 

Weight of metals per cubic inch 186 

Weights of metals 188 

White alloy, high electrical resistance 34 

White anti-friction metals, classification of 107 

White brass 83-132-136 

White brass mixtures : 137 

White metals 133 

White metal mixtures, special 138 

Wolframinium 99 

Wood's alloy 140 

Working properties of alloys and metals 30 

Work of the Alchemists 5 

Yellow brass 83 

Yellow metal 78 

Zinc-aluminum 153 

Zinc-aluminum alloys 97 

Zinc amalgam 143 

Zinc and aluminum 92 

Zinc in bearing bronzes 104 

Zisikon 149 



267 90 



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